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WORKS  OF  Prof.  E.  A.  RUDDIMAN 

PUBLISHED   BY 

JOHN  WILEY  &  SONS. 


Incompatibilities  in  Prescriptions. 

For  Students  in  Pharmacy  and  Medicine,  and 
Practising  Pharmacists  and  Physicians.  Third 
Edition,  Partly  Rewritten.  8vo,  vi  +  312  pages. 
Cloth,  $2.00. 

Whys  in  Pharmacy. 

A  Compilation  of  Reasons  Underlying  the  Princi- 
ples of  Pharmacy,  Supplemented  by  a  Table  of 
Equations,     izmo,  vi  +  196  pages.     Cloth,  $1.00 


WHYS  IN  PHARMACY 


A    COMPILATION  OF    REASONS    UNDERLYING    THE 

PRINCIPLES   OF  PHARMACY,  SUPPLEMENTED 

BY  A  TABLE  OF  EQUATIONS 


BY 


EDSEL   A.    RUDDIMAN,  Ph.M.,  M.D. 

Professor  of  Pharmacy  and  Materia  Medica  in  Vanderbilt  University 
Author  of  ""Incompatibilities  in  Prescriptions" 


FIRST   EDITION 

THIRD    THOUSAND. 


NEW  YORK 

JOHNWILEY^   &    SONS 

London:   CHAPMAN  &  HALL,  Limited 

1911 


t^^ 


Copyright,  1906 

BY 

EDSEL  A.  RUDDIMAN 


THE    SCIENTIFIC    PRESS 

ROBERT   DRUMMONO   AND   COMPANr 

BROOKLYN,    N.    Y. 


PREFACE. 


In  the  publication  of  these  questions  and  answers 
the  writer  claims  no  originality.  The  only  reason  he 
has  for  putting  them  into  book  form  is  because  he 
has  had  numerous  requests  for  them  from  his  students 
and  the  readers  of  the  Bulletin  of  Pharmacy  in  which 
much  of  the  matter  has  been  printed. 

Early  in  the  course  of  the  author's  teaching  he  came 
to  the  conclusion  that  the  teaching  of  the  reasons  for 
the  use  of  certain  ingredients  and  for  mixing  these 
in  certain  orders  is  one  of  the  most  important  parts 
of  the  work — more  essential  than  the  memorizing  of 
formulas.  The  book  is  not  intended  as  a  quiz  com- 
pend,  but  as  an  aid  to  those  who  wish  to  get  at  the 
principles  underlying  the  subject.  At  first  only  the 
questions  were  written,  leaving  the  student  to  look 
up  the  answers  for  himself.  Mr.  Joseph  Helfman, 
editor  of  the  Bulletin  of  Pharmacy,  suggested  that 


111 


265648 


IV  PREFACE. 

more  good  would  be.  done  the  readers  by  giving  the 
answers  as  well,  and  the  writer  came  to  the  same 
conclusion. 

Acknowledgment  is  made  of  the  free  use  of  Cas- 
pari's  Treatise  on  Pharmacy  and  other  books  on 
pharmacy  and  chemistry. 

Edsel  a.  Ruddiman. 

Nashville,  October,  1905. 


CONTENTS. 


PAGE 

PREPARATIONS 1 

Waters 2 

Cerates 5 

Papers q 

Collodions 7 

Decoctions 8 

Elixirs 8 

Plasters 11 

Emulsions 12 

Percolation  and  Fluid  Extracts 14 

Solid  Extracts 22 

Glycerites 25 

Infusions 26 

Liniments 27 

Solutions 29 

Masses 38 

Mixtures 40 

Mucilages 41 

Oleates 42 

Oleoresins 43 

Oils 44 

Pills 50 

Powders 54 

Resins 59 

Spirits 59 

Suppositories 62 

Syrups 63 

Tinctures. 70 

Troches 77 

Ointments 77 

Wines 82 

V 


VI  CONTENTS. 

PAGE 

CHEMICALS 83 

Acids 83 

Inorganic  Compounds 92 

Aluminum  Salts 92 

Ammonium  Salts 93 

Antimony  Salts 93 

Silver  Salts 94 

Gold  Salts 94 

Bismuth  Salts 94 

Calcium  Salts 95 

Chromium  Salts 96 

Iron  Salts 97 

Mercury  Salts 102 

Magnesium  Salts 107 

Lead  Salts 108 

Potassium  Salts 109 

Sodium  Salts 113 

Sulphur 115 

Zinc  Salts 115 

ORGANIC   DRUGS 117 

ALKALOIDS.    DRUG  ASSAYS 126 

PRESCRIPTIONS 138 

MISCELLANEOUS 160 

EQUATIONS 165 


*    J    K      9 


WHYS  IN  PHARMACY- 


PREPARATIONS. 


WATERS. 


Why  is  purified  talc  used  in  making  many  official 
waters?  Because  it  breaks  the  volatile  substances 
into  minute  particles,  thereby  increasing  the  surface 
exposed  to  the  solvent  action  of  the  water;  and  it 
also  removes  the  excess  of  the  volatile  substances, 
making  a  clear  solution.  At  the  same  time,  talc  is 
not  appreciably  soluble  in  water. 

Why  is  calcium  phosphate  of  the  1890  method 
objectionable?  It  is  slightly  soluble,  particularly  in 
the  presence  of  acid  substances,  and  many  waters 
made  with  it  seem  to  be  good  media  for  the  growth 
of  micro-organisms. 

Why  is  magnesium  carbonate  an  objectionable 
substitute  for  purified  talc?  The  commercial  article 
contains  some  hydrate  which  is  somewhat  soluble  in 
water,  making  a  solution  that  is  sufficiently  alkaline 
to  cause  the  formation  of  a  precipitate  when  any  one 


^  V/HYS   ipj"   PHARMACY. 

of  a  number  of  metallic  or  alkaloidal  salts  is  added 
to  the  water.  Moreover,  magnesium  carbonate  com- 
bines with  acids  that  are  normally  present  in  some 
of  the  oils,  forming  soluble  compounds  which  may 
give  colored  preparations. 

Why  is  the  1880  method  of  using  cotton  objection- 
able? Because  it  does  not  divide  the  oil  into  such 
fine  globules,  it  takes  more  time,  more  oil  is  wasted, 
and  sometimes  oil  globules  are  washed  into  the 
filtrate. 

Why  is  a  jug  better  than  a  bottle  in  making  flavor- 
ing waters  by  mixing  oil  with  hot  water?  The  rough 
surface  of  the  jug  helps  to  break  up  the  oil. 

Why  are  waters  made  by  distillation  frequently 
of  finer  flavor  than  when  made  by  solution  of  oil? 
Acids  and  ethers  present  in  some  plants  pass  over 
with  the  oil  and  modify  the  odor. 

Why  is  the  addition  of  alcohol  as  a  preservative 
objectionable?  A  small  amount  helps  rather  than 
hinders  decomposition,  while  a  large  amoimt  is 
objectionable  on  account  of  its  therapeutic  action. 

Why  is  a  plug  of  cotton  put  into  the  neck  of  the 
stock-bottle  when  a  distilled  or  flavoring  water  is  re- 
moved by  siphoning?  As  the  water  is  drawn  off 
air  enters  the  bottle  and  must  pass  through  the  cotton 
which  filters  out  dust  and  germs,  protecting  the  water 
from  the  growth  of  microscopic  organisms. 

Why  is  it  objectionable  to  use  water  that  has  not 
been  distilled  for  making  preparations  or  filling  pre- 
scriptions?    Ordinary  water  ma}^  contain  ammonia, 


PREPARATIONS.  3 

carbon  dioxide,  inorganic  salts,  organic  matter,  and 
bacteria. 

Why  is  the  hardness  of  water  called  '' temporary 
hardness"  when  it  is  due  to  calcium  carbonate  in 
solution?  The  calcium  carbonate  is  held  in  solu- 
tion by  carbon  dioxide  and  boiling  drives  this  off 
and  precipitates  the  salt,  making  the  water  soft. 

Why  does  the  U.  S.  P.  direct  that  the  first  100  cc. 
of  distillate  be  thrown  away  in  making  distilled 
water?  Because  it  holds  in  solution  practically  all 
of  the  gases  that  were  held  in  solution  in  the  1000  cc. 
before  distillation. 

Why  are  the  last  100  cc.  left  in  the  retort  in  making 
distilled  water?  If  distillation  were  carried  too  far 
some  inorganic  matter  might  be  carried  over  me- 
chanically, or  some  of  the  organic  matter  decom- 
posed and  volatilized,  or  injury  might  result  to  the 
retort. 

Why  should  the  container  for  distilled  water  be 
rinsed  with  hot  distilled  water  just  before  being  filled? 
To  wash  out  impurities  and  destroy  all  germs. 

Why  is  condensed  steam  from  boiler-pipes  an  ob- 
jectionable substitute  for  distilled  water?  It  is 
generally  contaminated  with  oil  from  the  boiler  and 
iron  from  the  pipes. 

Why  is  ammonia  water  sometimes  marked  '^FFF" 
or  ^^FFFF"?  This  refers  to  "the  strength,  but  the 
samples  marked  the  same  vary  considerably.  ^^F" 
stands  for  fortis,  strong,  ^'FFF"  for  triple  strength. 

Why  should  stronger  ammonia  water  be  kept  in 


4  WHYS   IN    PHARMACY. 

"partially"  filled  bottles?  The  gas  is  readily  given 
up  by  the  water  and  the  pressure  might  easily  be- 
come so  great  as  to  burst  the  bottle. 

Why  is  talc  not  used  in  making  bitter  almond 
water?  Oil  of  bitter  almonds  is  sufficiently  soluble 
in  water  so  that  a  clear  solution  results  when  the 
desired  amount  of  oil  is  used. 

Why  is  natural  oil  sometimes  preferable  to  the 
artificial  oil  of  bitter  almonds?  The  artificial  oil 
does  not  contain  hydrocyanic  acid^  which  is  the  seda- 
tive principle. 

Why  should  stronger  orange  flower  water  be  kept 
in  loosely-stoppered  bottles?  If  kept  tightly  stop- 
pered it  acquires  a  disagreeable  foreign  odor^  which 
may  be  dissipated  by  exposure  to  air. 

Why  is  alcohol  used  in  making  camphor  water? 
To  dissolve  the  camphor  so  that  it  can  be  more 
thoroughly  distributed  through  the  talc. 

Why  is  the  greater  part  of  the  alcohol  allowed  to 
evaporate  spontaneously?  If  the  alcohol  were  not 
evaporated  the  water  would  be  more  than  saturated. 
If  heat  were  used  to  evaporate  it  some  camphor 
would  be  volatilized. 

Why  should  manganese  dioxide  not  be  too  fine  or 
hydrochloric  acid  too  concentrated  in  making  chlo- 
rine water  (1890)?  In  either  case  the  generation  of 
gas  at  first  would  be  too  fast. 

Why  should  chlorine  water  be  kept  in  a  cool, 
dark  place?  Heat  volatihzes  the  chlorine  and  light 
changes  it,  forming  hydrochloric  acid. 


i?REPARATIONS.  5 

Why  should  an  excess  of  chloroform  be  kept  in 
the  container  of  chloroform  water?  So  as  to  keep 
a  saturated  solution  at  all  times,  chloroform  being 
very  volatile. 

Why  should  chloroform  water  be  kept  in  an  am- 
ber-colored bottle?  Light  decomposes  it,  forming 
hydrochloric  acid. 

Why  is  barium  dioxide  hydrated  and  kept  cold  in 
making  hydrogen  dioxide  water  (1890)?  Cold  aids 
hydration  and  hydration  causes  a  larger  yield. 

Why  is  phosphoric  acid  used  in  preference  to  other 
acids  in  making  hydrogen  dioxide  water?  Experi- 
ence shows  that  phosphoric  acid  gives  a  rather  larger 
yield. 

Why  is  a  small  amount  of  acid  left  in  hydrogen 
dioxide  water?  The  acid  tends  to  prevent  decom- 
position of  hydrogen  dioxide. 

Why  should  hydrogen  dioxide  water  be  kept  in 
loosely  stoppered  containers?  Because  it  slowly  de- 
composes, hberating  oxygen,  and  sufficient  pres- 
sure may  be  produced  to  burst  the  bottle.  Keeping 
the  bottle  tightly  stoppered  does  not  seem  to  retard 
decomposition,  but  keeping  in  the  dark  does. 

CERATES. 

AVhy  in  making  cerates  is  it  best  to  melt  the  ingre- 
dient having  the  highest  melting-point  first  and 
then  the  one  having  the  next  highest  melting-point? 
If  they  are  all  heated  together  the  one  having  the 


6  WHYS  IN    PHARMACY. 

lowest  melting-point  may  be  decomposed  by  the 
temperature  necessary  to  melt  the  one  having  the 
highest  melting-point. 

Why  are  the  melted  ingredients  stirred  constantly 
until  cold  in  making  simple  cerate?  To  prevent 
separation^  wax  sohdifying  first  would  tend  to 
separate. 

Why  is  Hquid  petrolatum  used  in  making  cerate 
of  cantharides?  By  macerating  cantharides  with 
liquid  petrolatum  the  cantharidin  is  more  com- 
pletely dissolved  by  the  base.  This  preparation 
does  not  now  have  the  odor  of  turpentine  as  did 
that  of  the  1890  edition. 

Why  is  wool-fat  used  in  making  cerate  of  lead 
subacetate?  It  aids  the  mixing  of  the  aqueous 
solution. 

Why  are  paraffin^  petrolatum,  and  camphor  used 
in  place  of  camphor  cerate  in  making  cerate  of  lead 
subacetate?  Made  with  these  the  cerate  keeps 
better.  The  cerate  made  by  the  1890  formula  soon 
turns  yellow  and  rancid. 

Why  does  the  U.  S.  P.  direct  that  resin  cerate  be 
cooled  mth  occasional  stirring?  Continuous  stirring 
incorporates  some  air  and  is  not  necessary  as  the 
cerate  cools  to  a  homogeneous  mass  without  it. 

PAPERS. 

Why  is  the  fixed  oil  removed  from  mustard  in 
making  mustard  paper?  The  fixed  oil  is  inert  and 
makes  the  paper  greasy  and  unsightly. 


PREPARATIONS.  7 

Why  should  mustard  paper  be  dipped  into  warm 
water  just  before  applying?  Water  is  necessary  to 
allow  the  ferment  to  act  on  the  sinigrin,  forming 
the  volatile  oil  of  mustard.  Water  also  softens  the 
paper.  Hot  water  must  not  be  used  because  it 
destroys  the  activity  of  the  ferment  and  prevents 
the  formation  of  the  volatile  oil. 

COLLODIONS. 

Why  should  the  neck  of  a  collodion  bottle  be 
thoroughly  wiped  out  after  pouring  out  some  of  the 
collodion?  If  the  stopper  is  inserted  without  this 
wiping  it  is  hkely  to  get  fixed  in  so  tightly  that  it 
is  necessary  to  break  the  bottle  the  next  time  collodion 
is  wanted. 

Why  is  alcohol  used  in  making  collodion?  Ether 
alone  does  not  dissolve  guncotton  as  readily  as 
when  it  contains  a  little  alcohol. 

Why  is  cantharides  exhausted  with  chloroform 
instead  of  with  collodion  in  making  cantharidal 
collodion?  Chloroform  leaves  a  residue  which  makes 
a  nearly  clear  solution  with  collodion.  Collodion  is 
so  tliick  that  it  cannot  be  readily  separated  from 
the  insoluble  part  of  the  flies  if  it  were  used  as  the 
macerating  fluid.  Ether  is  probably  as  good  as 
chloroform. 

Why  is  plain  collodion  better  than  flexible  collo- 
dion for  putting  on  small  cuts?  Plain  collodion  con- 
tracts more  than  the  flexible  and  draws  the  lips  of 
the  wound  together  more. 


8  WHYS   IN   PHARM,\CY. 

DECOCTIONS. 

Why  should  decoctions  not  be  made  by  dilution 
of  fluid  extracts?  Water  does  not  dissolve  the 
same  principles  that  are  generally  in  solution  in 
the  fluid  extract,  and  consequently  the  therapeutic 
action  is  not  the  same. 

Why  in  making  decoctions  are  drugs  put  into 
cold  water  instead  of  hot  water  as  in  infusions? 
Drugs  suitable  for  decoctions  more  often  contain 
albuminous  matter,  which  if  coagulated  at  first  by 
hot  water  would  make  the  extraction  of  the  active 
principles  more  difficult. 

Why  should  hard  or  prolonged  boiling  be  avoided? 
The  active  principle  may  be  decomposed  or  the 
decoction    loaded    with    tannin    and    inert    matter. 

Why  should  decoctions  be  strained  at  40"  C.  rather 
than  strained  when  cold?  Hot  water  sometimes 
takes  out  active  matter  that  is  precipitated  from 
cold  water.  By  straining  when  warm  this  is  left 
in  and  can  be  mixed  with  the  liquid. 

Why,  in  making  decoction  of  cetraria  (1890),  is 
cetraria  macerated  in  cold  water  which  is  subse- 
quently thrown  away?  Cold  water  takes  out  the 
bitter  principle,  making  the  decoction  more  palatable. 

ELIXIRS. 

Why  is  purified  talc  used  in  making  aromatic 
ehxir?  Because  the  oils  in  compound  spirit  of 
orange  are   precipitated  by  the  water   and   syrup, 


PREPARATIONS.  9 

and  an  insoluble  powder  is  necessary  to  remove  the 
excess. 

Why  should  the  filter  be  wetted  with  a  mixture 
contaimng  at  least  twenty-five  per  cent,  alcohol 
instead  of  wetted  with  water  in  filtering  aromatic  or 
other  eUxirs?  Water  generally  gives  a  turbid  filtrate, 
due  to  separation  of  small  globules  of  oil. 

Why  do  some  elixirs  give  a  turbidity  with  a  small 
amount  of  water  but  a  clear  solution  with  a  large 
amount?  Aromatic  elixir  is  a  saturated  solution 
of  oils  which  are  thrown  out  of  solution  by  a  small 
amount  of  water  but  redissolved  by  a  larger  amount. 

Why  is  carmin  generally  not  a  good  coloring- 
agent  for  ehxirs?  Elixirs  are  frequently  acid  and 
acids  precipitate  carmin. 

Why  are  ammonia  water  and  acetic  acid  used  in 
making  elixir  of  iron,  quinine,  and  strychnine  phos- 
phates? To  make  ammonium  acetate  which  tends 
to  prevent  the  precipitation  of  the  iron  phosphate. 

Why  do  eUxirs  containing  the  soluble  phosphate 
of  iron  with  quinine  sulphate  so  often  precipitate? 
Frequently  the  quinine  sulphate  is  slightly  acid,  or 
an  acid  is  added  to  aid  the  solution  of  the  quinine, 
and  acid  precipitates  the  insoluble  phosphate  of  iron. 

Why  is  potassium  citrate  used  in  making  elixir  of 
sahcyUc  acid,  N.  F.?  Potassium  citrate  aids  the 
solution  of  salicylic  acid,  possibly  forming  potassium 
salicylate  and  citric  acid. 

Why  is  ammonia  water  used  in  elixir  of  ammonium 
valerate,  N.  F.?    Ammorium  valerate,  on  exposure. 


10  WHYS    IN    PHARMACY, 

slowly  loses  ammonia,  liberating  the  insoluble  liquid 
valeric  acid;  ammonia  combines  with  this. 

Why  is  anethol  preferred  to  oil  of  anise  in  elixir  of 
anise,  N.  F.?     It  has  a  finer  odor  and  flavor. 

Why  is  ammonia  water  used  in  elixir  of  bismuth, 
N.  F.  ?  Because  the  bismuth  and  ammonium  citrate 
loses  ammonia,  leaving  the  insoluble  bismuth  citrate, 
and  ammonia  combines  with  it  to  form  a  soluble 
compound. 

Why  is  magnesium  carbonate  used  in  elixir  of 
buchu,  N.  F.?  On  adding  the  elixir  and  syrup  to 
the  fluid  extract  of  buchu  resinous  matter  is  pre- 
cipitated; magnesium  carbonate  aids  the  removal 
of  this. 

Why  is  elixir  of  cinchona,  N.  F.,  allowed  to  stand 
as  long  as  possible  before  filtering?  So  as  to  let  the 
fine  precipitate  which  is  formed  settle  as  it  tends  to 
clog  the  filter. 

Why  are  citric  acid  and  ammonia  water  used  in 
making  elixir  of  cinchona,  iron,  and  calcium  lacto- 
phosphate,  N.  F.?  The  ammonium  citrate  formed 
prevents  the  precipitation  of  iron  that  might  other- 
wise take  place. 

Why  is  talcum  used  in  preference  to  calcium  phos- 
phate in  making  compound  digestive  elixir,  N.  F.? 
Calcium  phosphate  would  dissolve  in  the  hydro- 
chloric and  lactic  acids,  while  purified  talcum  does 
not. 

Why  is  powdered  pumice-stone  used  in  making 
aromatic  elixir  of  yerba  santa,  N.  F.?    Some  kind  of 


PREPARATIONS.  11 

insoluble  powder  must  be  used  to  aid  the  removal 
of  the  precipitated  resinous  matter  from  the  fluid 
extract,  and  it  is  thought  by  some  that  the  use  of 
pumice-stone  gives  a  finer  flavor  to  the  finished 
product  than  does  calcium  phosphate,  possibly  by 
clearing  the  mixture  without  removing  so  much  of 
the  flavoring  principle. 

Why  are  ammonia  water  and  solution  of  tersulphate 
of  iron  used  in  making  elixir  of  gentian,  N.  F.? 
Ammonia  converts  the  ferric  sulphate  into  the  in- 
soluble ferric  hydrate,  and  this  combines  with  tannin 
in  the  compound  spirit  of  cardamom  to  form  an  in- 
soluble tannate  of  iron  which  may  be  removed  by 
filtration;  the  elixir  can  then  be  dispensed  with 
iron  salts. 

Why  is  the  elixir  of  pepsin  and  bismuth,  N.  F.,  of 
doubtful  therapeutic  value?  Because  in  getting  the 
bismuth  and  ammonium  citrate  into  solution  a  slight 
excess  of  ammonia  is  used,  making  the  solution  a 
little  alkahne;  and  pepsin  is  said  to  be  rendered  en- 
tirely inert  by  alkaUes. 

PLASTERS. 

Why  is  a  plaster  made  with  a  rubber  base  supposed 
to  be  less  effective  than  one  made  with  the  lead- 
plaster  base?  It  is  claimed  that  a  rubber-base 
plaster  does  not  give  up  the  medicinal  matter  as 
readily  as  one  made  with  lead  plaster. 

Why  should  spread  plasters  have  a  quarter  to 


12  WHYS   IN   PHARMACY. 

a  half  inch  of  leather  or  cloth  not  covered  by  the  mass? 
The  plaster  mass  often  softens  with  the  heat  of  the 
body  and  may  ooze  out,  soiling  and  sticking  to  the 
clothing. 

Why  are  perforated  plasters  preferred  to  those  not 
perforated?  They  are  more  pHable,  and  they  allow 
the  escape  of  exhalations  of  the  skin,  thus  being 
more  comfortable. 

Why  are  oleate  of  mercury  and  hydrous  wool-fat 
used  in  mercurial  plaster?  To  aid  the  division  of 
metallic  mercury  used  in  the  plaster. 

Why  is  the  reverse  side  of  court  plaster  (1890) 
coated  with  tincture  of  benzoin?  To  make  it  im- 
pervious to  air  and  water. 

Why  is  glycerin  used  in  making  court  plaster 
(1890)  ?  It  makes  the  gelatin  more  flexible  and  pre- 
vents its  cracking. 

Why  is  water  used  in  making  lead  plaster (1890)? 
It  enters  into  chemical  reaction  and  tends  to  prevent 
the  burning  of  the  organic  matter. 

Why  is  lead  plaster  washed  with  hot  water?  To 
soften  the  plaster  so  that  the  sodium  acetate  may  be 
more  easily  washed  out. 

EMULSIONS. 

Why  must  the  mortar  be  perfectly  dry,  and  the  oil 
free  from  moisture,  when  emulsions  are  made  by 
putting  the  oil  and  acacia  into  the  mortar  and  then 
adding  the  water?    Because  the  presence  of  even  a 


PREPARATIONS.  13 

small  amount  of  water  forms  a  mucilage  with  some 
acacia  before  it  is  mixed  well  with  the  oil,  and  thus 
"  cracks  "  the  emulsion 

Why  do  emulsions  of  volatile  oils  separate  more 
quickly  than  those  of  fixed  oils?  As  a  rule  the  emul- 
sion is  thinner. 

Why  are  emulsions  of  the  volatile  oils  and  light 
H  quids  best  made  in  a  bottle  while  emulsions  of  fixed 
oils  are  made  in  a  mortar?  The  ingredients  in  an 
emulsion  of  a  fixed  oil  make  so  tliick  a  hquid  that 
they  cannot  be  quickly  and  well  mixed.  The  emul- 
sion of  a  volatile  liquid  is  generally  so  thin  that  it  can 
be  readily  mixed  by  agitation. 

Why  are  glass  or  porcelain  mortars  not  so  good 
for  making  emulsions  as  Wedgewood?  They  are  too 
smooth. 

Why  are  powdered  gum-resins  not  as  good  for 
making  emulsions  as  the  tears  or  masses?  Frequently 
considerable  volatile  matter  is  driven  off  in  the  drying 
which  is  necessary  before  powdering. 

Why  is  it  not  necessary  to  add  an  emulsifying 
agent  in  making  many  seed  and  gum-resin  emul- 
sions? Because  gummy  matter  is  already  present  in 
the  drugs. 

Why  is  an  emulsion  made  with  acacia  whiter  than 
one  made  with  most  other  emulsifying  agents?  Be- 
cause acacia  has  the  property  of  dividing  oil  into 
smaller  globules,  and  the  smaller  the  globules  the 
whiter  the  emulsion. 

Why  should  pressure  with  the  pestle  not  be  used 


14  WHYS    IN    PHARMACY. 

in  making  emulsions  in  the  mortar?  Because  pres- 
sure generates  heat,  and  heat  tends  to  prevent  emul- 
sification. 

Why  is  tragacanth  sometimes  used  in  connection 
with  acacia  in  emulsions?  Acacia  is  a  good  emulsi- 
fying agent,  while  tragacanth  is  useful  to  keep  the 
emulsified  oil  from  separating  from  the  aqueous 
portion  after  the  product  is  made. 

Why  is  tincture  of  quillaja  objectionable  as  an 
emulsifying  agent?  It  has  some  physiological  action 
of  its  own. 

Why  should  strongly  alcoholic  fluids  be  diluted 
with  water  before  being  mixed  with  emulsions? 
Acacia,  being  insoluble  in  alcohol,  is  thrown  out  of 
solution,   and   the  emulsion  is  thus  broken. 

Why  is  expressed  oil  of  almonds  used  in  making 
emulsion  of  chloroform?  Because  it  is  a  fixed  oil, 
and  fixed  oils  help  to  emulsify  chloroform  and  keep 
it  in  suspension. 

Why,  in  making  emulsion  of  cod  liver  oil  with 
hypophosphites,  are  the  syrup  and  solution  of  hypo- 
phospites  added  to  the  primary  enmlsion  instead 
of  being  used  in  making  the  primary  emulsion? 
Sugar  and  salts  tend  to  prevent  emulsification. 

PERCOLATION  AND  FLUID   EXTRACTS. 

Why  was  the  term  fluidextractum  coined  and  used 
in  the  U.  S.  P.?  In  order  to  separate  the  fluid  from 
the  solid  extracts. 


PREPARATIONS.  15 

Why  is  a  slightly  conical  percolator  better  than  a 
cylindrical  one?  Because  when  a  drug  swells  after 
being  put  into  the  percolator,  it  has  a  chance  to 
press  upward,  and  therefore  does  not  become  so 
firmly  packed. 

Why  is  a  percolator  only  slightly  conical  better 
than  one  more  decidedly  so?  In  a  conical  per- 
colator the  menstruum  which  passes  through  the 
drug  near  the  sides  of  the  vessel  passes  through 
only  a  short  column  of  the  drug,  soon  striking  the 
sides  of  the  percolator  and  therefore  not  becoming 
nearly  saturated  with  the  soluble  constituents  of 
the  drug.  In  a  percolator  which  is  nearly  cylindrical 
the  columns  of  drug  are  more  nearly  uniform  in 
length,  and  the  drug  is  consequently  more  uniformly 
exhausted. 

Why  is  a  conical  percolator  desirable  when  the 
menstruum  is  strongly  aqueous?  Water  swells  the 
drug  much  more  than  alcohol,  and  the  conical  per- 
colator gives  the  drug  a  chance  to  expand. 

Why  is  it  desirable  to  have  a  percolator  with  a 
stop-cock?  Because  the  rate  of  flow  can  be  much 
more  easily  controlled. 

Why  must  tin  percolators  not  be  used  in  making 
fluid  extracts  of  nux  vomica,  conium,  and  sangui- 
naria?  Because  the  menstruums  for  these  contain 
acid  which  would  attack  the  percolator. 

Why  is  the  drug  dampened  before  being  put  into 
the  percolator?  The  dampened  drug  can  be  packed 
more  firmly  and  uniformly,  and  the  finer  particles 


16  WHYS    IN    PHARMACY. 

of  the  drug  are  not  so  liable  to  be  washed  down  to 
the  apex  of  the  percolator. 

Why  is  it  advisable  to  allow  the  drug  to  stand 
after  dampening  before  being  put  into  the  percolator? 
Because  the  drug  has  a  chance  to  swell,  and  there 
is  not  the  liabiUty  of  its  becoming  packed  so  hard 
in  the  percolator  as  to  prevent  the  flow  of  the  men- 
struum. 

Why  should  the  drug  be  packed  in  layers  and 
not  be  put  all  into  the  percolator  at  one  time  and 
packed?  If  all  is  put  in  at  once  it  will  be  packed 
too  tight  at  the  top  and  not  tight  enough  at  the 
bottom. 

Why  can  a  drug  be  packed  firmly  when  the 
menstruum  is  alcohol?  Because  alcohol  does  not 
swell  the  drug,  does  not  dissolve  so  much  mucilaginous 
matter,  and  so  does  not  become  so  thick  and  viscid. 

Why  should  the  drug  at  the  bottom  of  the  perco- 
lator be  packed  more  loosely  than  that  at  the  top? 
Because,  in  cases  of  certain  drugs,  when  the  men- 
struum has  reached  the  lower  portion  of  the  drug 
it  is  so  loaded  with  the  matter  which  has  been 
dissolved  that  it  is  too  thick  to  run  through  the 
drug  if  it  is  tightly  packed. 

Why  is  it  advisable  to  put  a  disk  of  paper  or  a 
sieve  on  the  top  of  the  drug  in  the  percolator? 
Unless  something  of  the  kind  is  used  the  menstruum, 
when  it  is  poured  on,  will  wash  a  cavity  in  the 
drug,  and  this  will  tend  to  prevent  the  menstruum 
from  passing  through  uniformly. 


PREPARATIONS.  17 

Why  is  the  drug  macerated  for  forty-eight  hours 
before  percolating?  This  is  for  the  purpose  of  allow- 
ing the  menstruum  to  permeate  every  particle  of  the 
drug  and  dissolve  the  active  matter. 

Why  must  the  drug  be  kept  covered  with  the 
menstruum  during  percolation?  If.  when  fresh 
menstruum  is  poured  on,  the  menstruum  has  been 
allowed  to  drain  off,  it  will  rush  through  between 
the  particles  of  drug  without  entering  them  or 
dissolving  the  matter  contained  in  them. 

Why  should  percolation  proceed  slowly?  So  as 
to  give  the  menstruum  an  opportunity  to  dissolve 
all  of  the  matter  that  it  will,  thus  reducing  the 
amount  of  alcohol  used,  and  the  amount  of  evapo- 
ration necessary. 

Why  is  evaporation  necessary  in  making  fluid 
extracts?  Because  the  standard  for  fluid  extracts 
requires  that  one  cubic  centimeter  shall  represent 
one  gram  of  the  drug,  and  it  is  impossible  to  exhaust 
the  drug  without  getting  more  percolate  than  this; 
drugs  require  from  two  to  five  times  their  quantity 
of  menstruum. 

Why  is  the  second  percolate  evaporated  down 
to  a  soft  extract  instead  of  only  so  far,  that  with 
the  reserved  portion,  it  will  make  up  the  required 
amount?  By  the  time  the  evaporation  has  been 
carried  to  the  point  where  the  residue  will  give  the 
required  amount  with  the  reserved  portion,  all  of 
the  alcohol  has  been  driven  off,  leaving  an  aqueous 
mixture,  and  the  water  of  tliis  will  cause  precipita- 


18  WHYS   IN    PHARMACY. 

tion  when  added  to  the  reserved  portion;  it  is  neces- 
sary therefore  to  evaporate  off  the  water. 

Why  does  the  quantity  of  the  first  percolate — the 
reserved  portion — vary  with  different  drugs?  Be- 
cause different  drugs  yield  different  quantities  of 
extractive  matter  when  the  second  percolate  is 
evaporated.  When  the  drug  yields  a  large  quan- 
tity of  extractive  matter  the  quantity  of  the  reserved 
first  percolate  is  smaller,  so  that  it  can  be  mixed 
with  the  residue  without  getting  too  large  a  volume 
of  the  finished  product. 

Why  is  it  important  that  the  first  percolate  con- 
tain most  of  the  active  principle?  Because  the 
first  percolate  is  not  heated,  and  heat  often  destroys 
some  of  the  active  principles. 

Why  is  a  clear  solution  not  obtained  when  the 
residue  from  the  second  percolate  is  mixed  with 
the  first  percolate?  Because  some  of  the  extractive 
matter  which  is  dissolved  by  the  original  menstruum 
is  rendered  insoluble  by  heat  in  evaporating. 

Why  is  it  best  to  keep  the  temperature  of  evapora- 
tion down  to  about  50°  C.  ?  Because  higher  heat  in 
the  presence  of  moisture  frequently  decomposes  the 
active  principles. 

Why  do  fluid  extracts  deposit  solid  matter  after 
being  made?  Because  if  heat  has  been  used  the 
extractive  matter  that  has  been  changed  precipitates 
slowly;  moreover,  change  in  the  temperature  and 
light,  and  the  loss  of  alcohol,  cause  a  deposit  of 
inert  matter. 


PREPARATIONS.  19 

Why  does  precipitation  sometimes  take  place  in 
a  percolate  although  the  same  strength  of  alcoholic 
menstruum  is  used  throughout?  Because  the  sol- 
vent power  of  the  menstruum  varies  at  different 
stages  of  the  percolation. 

Why  tioes  the  solvent  power  of  the  menstruum 
vary  at  different  stages  of  the  percolation?  The 
menstruum  dissolves  certain  principles  out  of  the 
drug,  and  the  solution  so  made  dissolves  other 
matter  that  is  not  soluble  in  the  original  menstruum. 

Why  is  glycerin  used  as  part  of  the  menstruum 
in  making  some  fluid  extracts?  Glycerin  plays  the 
part  of  a  preservative  in  some  cases  and  in  others 
it  dissolves  tannin  and  keeps  it  from  precipitating 
subsequently. 

Why  is  glycerin  put  into  the  first  part  of  the  men- 
struum only  and  not  in  all  of  the  menstruum?  Glyc- 
erin is  non- volatile  and  cannot  be  evaporated  with 
the  alcohol  and  water  in  evaporating  the  second 
percolate;  consequently  the  volume  of  the  finished 
product  would  be  too  large. 

Why  is  a  fluid  extract  made  by  repercolation 
better  than  one  made  by  simple  percolation?  Be- 
cause it  does  not  precipitate  so  much  and  has  not 
been  hurt  by  heat. 

Why  is  repercolation  not  more  used  than  it  is? 
The  objections  are  that  more  time  is  required,  and 
besides  some  of  the  processes  require  the  keeping 
of  dilute  percolates. 

Why  is  it  best  to  keep  fluid  extracts  in  amber- 


20  WHYS  IN  PHARMACY. 

colored   bottles?    Light   causes   decomposition   and 
precipitation.     Blue  glass  does  not  protect. 

Why  is  the  word  ''Radicis'^  introduced  into  the 
official  title  of  the  fluid  extract  of  belladonna?  To 
show  that  it  is  made  from  the  root,  the  extract  and 
tincture  being  made  from  the  leaves.  *" 

Why  is  acetic  acid  used  in  fluid  extract  of  conium? 
The  acid  converts  the  alkaloid  coniine  into  the  ace- 
tate, which  is  more  stable  and  less  easily  volatilized. 

Why  is  acetic  acid  used  in  fluid  extract  of  ergot? 
To  make  the  alkaloids  more  stable. 

Why  is  ammonia  used  in  fluid  extract  of  licorice? 
Glycyrrhizin  probably  occurs  as  the  acid  ammonium 
salt  of  glycyrrhizic  acid.  Ammonia  converts  it  into 
the  neutral  salt,  which  is  more  soluble  and  sweeter. 

Why  is  glycerin  used  in  the  fluid  extract  of  gly- 
cyrrhiza?  As  a  preservative  (the  amount  of  alcohol 
being  small)  and  to  prevent  precipitation.  This  fluid 
extract  will  now  mix  with  water  without  precipita- 
tion. 

Why  is  glycyrrhiza  exhausted  with  boihng  water? 
This  is  a  good  solvent  for  the  sweet  principle.  The 
concentrated  percolate  is  mixed  with  alcohol  to  pre- 
cipitate albuminous  matter.  The  filtered  hquid  is 
evaporated  to  get  rid  of  most  of  the  alcohol  as  the 
finished  product  only  contains  about  twenty  per  cent, 
by  volume  of  official  alcohol. 

Why  is  lupuhn  put  into  the  percolator  without 
dampening?  Lupulin  is  so  resinous  that  when 
moistened  with  alcohol  it  makes  a  mass  difficult  to 


PREPARATIONS.  21 

pack  in  such  a  manner  that  the  menstruum  will  run 
through. 

Why  is  acetic  acid  used  in  fluid  extract  of  nux 
vomica?  It  makes  the  alkaloid  more  soluble  and 
also  helps  to  soften  the  drug  so  that  it  may  be  more 
readily  extracted.     Digestion  softens  the  drug. 

Why  are  two  layers  sometimes  seen  in  the  fluid 
extract  of  nux  vomica  after  standing?  Nux  vomica 
contains  quite  a  large  amount  of  oil  which  is  left  in 
the  residue  after  evaporating  the  second  percolate, 
and  which  is  not  dissolved  in  the  first  percolate  since 
that  is  already  saturated  with  oil. 

Why  is  fluid  extract  of  wild  cherry  made  without 
evaporation?  Hydrocyanic  acid  is  the  active  prin- 
ciple and  is  readily  soluble  in  water.  It  is  very 
volatile  and  there  would  be  none  in  the  residue  if 
evaporation  were  directed. 

Why  is  magnesium  oxide  used  in  making  aromatic 
fluid  extract  of  cascara?  It  destroys  the  bitter  prin- 
ciple or  renders  it  insoluble.  The  drug  is  dried  to 
allow  the  use  of  a  uniform  menstruum. 

Why  is  acetic  acid  used  in  fluid  extract  of  blood- 
root?  It  makes  the  alkaloid  more  soluble  and  also 
prevents  the  subsequent  precipitation  of  matter. 

Why  is  solution  of  potassium  hydroxide  used  in 
fluid  extract  of  senega?  It  combines  with  pectin 
to  form  a  soluble  compound  and  thus  prevents  the 
gelatinization  which  would  otherwise  take  place. 

Why  is  such  strong  alcohol  used  in  making  fluid 
extract  of  senega  since  a  more  dilute  alcohol  would 


22  WHYS   IN   PHARMACY. 

take  out  the  active  principle?  The  stronger  men- 
struum does  not  take  out  so  much  pectin. 

Why  is  sodium  hydroxide  used  in  fluid  extract  of 
taraxacum?  To  prevent  subsequent  precipitation. 
This  fluid  extract  usuaUy  gives  a  very  heavy  deposit 
on  standing. 

Why  is  triticum  exhausted  with  boiUng  water, 
evaporated,  treated  with  alcohol,  and  filtered?  To 
get  rid  of  albuminous  matter. 

EXTRACTS. 

Why,  in  making  some  extracts,  is  the  menstruum 
water;  and  why,  in  making  corresponding  fluid  ex- 
tracts, is  it  a  mixture  of  alcohol  and  water?  Alcohol 
is  necessary  as  a  preservative  in  fluid  extracts  even 
when  the  active  principles  are  soluble  in  water.  In 
most  sohd  extracts  no  preservative  is  necessary. 

Why  does  an  extract  made  by  drying  the  juice  of 
a  fresh  drug  vary  more  than  that  made  from  a  dried 
drug?  The  amount  of  inert  matter  in  the  juice 
varies  more  than  that  dissolved  by  a  given  men- 
struum. 

Why  does  the  U.  S.  P.  not  direct  the  evaporation 
to  dryness  and  powdering  of  all  solid  extracts?  Be- 
cause the  extra  amount  of  heat  required  would  seri- 
ously impair  the  therapeutic  value  of  some  of  them. 

Why  do  extracts  vary  in  strength?  Manufacturers 
have  different  ideas  as  to  what  is  meant  by  ''pilular 
consistency";    some  extracts    absorb   moisture    on 


PREPARATIONS.  23 

keeping,  and  others  become  more  dry.  Different 
samples  of  the  drug  vary  in  the  amount  of  active 
matter  and  inert  matter  which  may  be  dissolved. 
More  heat  is  used  by  some  manufacturers  than  others. 

Why  do  some  unscrupulous  manufacturers  use  a 
m.enstruum  containing  more  water  than  that  directed 
by  the  U.  S.  P.?  By  so  doing  they  save  alcohol  and 
at  the  same  time  frequently  get  a  larger  yield  of 
extract,  since  water  has  a  greater  tendency  to  dis- 
solve extractive  matter. 

Why  is  glycerin  used  in  some  extracts?  It  is  used 
to  prevent  the  extract  from  becoming  hard  and  tough. 

Why  is  powdered  liquorice  used  in  making  some 
extracts?  To  keep  the  extract  in  the  form  of  a 
powder,  many  being  somewhat  hygroscopic. 

Why  are  extracts  sometimes  better  when  made 
by  evaporating  the  fluid  extract  than  by  following 
the  U.  S.  P.,  1890,  directions?  Because  the  larger 
portion  of  the  active  principles  will  not  have  been 
heated  so  long. 

Why  does  the  U.  S.  P.  direct  in  making  extracts 
of  belladonna,  henbane,  and  physostigma,  that  the 
first  portion  of  the  percolate  be  reserved  and  evapo- 
rated after  the  second  percolate  is  evaporated?  The 
active  principles  of  these  drugs  are  easily  decomposed 
by  heat,  and  the  largest  portions  of  them  are  sub- 
jected to  less  heat  by  following  the  directions. 

Why  is  such  a  large  proportion  of  water  used  in 
making  extract  of  aloes?  A  small  amount  of  water 
makes  a  concentrated  solution  of  the  soluble  con- 


24  WHYS   IN  PHARMACY. 

stituents,  and  this  solution  dissolves  the  inert  resin- 
ous matter.  By  using  a  large  amount  of  water 
the  solution  is  too  dilute  to  dissolve  the  resin. 

Why  is  acetic  acid  used  in  extract  of  colchicum? 
It  renders  the  alkaloid  colchicine  more  stable  and 
soluble. 

Why  does  the  U.  S.  P.  direct  colocynth  ''freed 
from  seeds"  in  making  extract  of  colocynth?  The 
seeds  contain  quite  a  large  percentage  of  fixed  oil 
which,  if  allowed  to  go  into  the  extract,  would 
prevent  the  extract  from  being  dried  and  pow- 
dered. 

Why  is  alcohol  used  in  making  compound  extract 
of  colocynth?  It  helps  to  thin  the  melted  aloes  and 
make  it  form  a  more  intimate  mixture  with  the 
other  ingredients. 

Why  are  water  and  hydrochloric  acid  used  in 
making  extract  of  ergot?  To  get  rid  of  foreign  and 
inert  matter  and  make  an  extract  that  is  soluble  in 
water.     Sodium  carbonate  is  used  to  neutralize  the 

acid. 

Why  is  cold  water  preferable  to  hot  water  in 
making  extract  of  gentian?  Cold  water  dissolves 
the  active  principles  as  well  as  hot  water,  while  it 
does  not  take  out  so  much  inert  matter. 

Why  is  the  aqueous  extract  of  gentian  boiled? 
BoiUng  coagulates  the  albuminous  matter,  which  is 
strained  out. 

Why  are  gentian  and  glycyrrhiza  macerated  for 
twenty-four  hours  after  dampening  before  being  put 


PREPARATIONS.  25 

into  percolators  in  making  the  extracts  of  these 
drugs?  Water  is  the  menstruum  used  and  it  causes 
the  drugs  to  swell  considerably;  by  allowing  them 
to  swell  before  putting  them  into  percolators  there  is 
less  danger  of  their  getting  packed  too  tight. 

Why  does  the  U.  S.  P.  introduce  the  word  ^^  Purum  " 
in  the  title  of  extract  of  glycyrrhiza?  To  distinguish 
it  from  the  commercial  extract,  which  is  not  entirely 
soluble. 

Why  is  ammonia  used  in  the  extract  of  glycyrrhiza? 
To  make  the  glycyrrhizin  more  soluble  and  sweeter. 

Why  is  hematoxylon  boiled  with  water?  The 
astringent  principle  is  not  very  readily  extracted 
by  cold  water,  but  is  by  boihng  water. 

Why  is  acetic  acid  used  in  extract  of  nux  vomica? 
It  helps  to  soften  the  drug  and  converts  the  alkaloids 
into  the  soluble  acetates.  Extracting  with  acetic 
acid  and  water  leaves  behind  the  fixed  oil  which 
caused  the  troublesome  part  of  the  1890  method. 
Alcohol  added  to  the  concentrated  aqueous  extract 
precipitates  inert  matter. 

Why  is  the  aqueous  infusion  of  quassia  boiled 
and  strained?    To  remove  the  albuminous  matter. 

GLYCERITES. 

Why  should  the  glycerites  be  protected  from 
the  air?  The  glycerin  present  in  them  is  hygro- 
scopic. 

Why   is   a   heat   of    140°  C.  directed   in   making 


26  WHYS  IN    PHARMACY. 

glycerite  of  starch?  Because  a  heat  much  lower 
than  this  would  not  rupture  the  enveloping  mem- 
brane of  the  starch  granule. 

Why  does  the  U.  S.  P.  direct  the  heating  of 
glycerin  and  boric  acid  until  a  definite  weight  is 
obtained,  in  making  glycerite  of  boroglycerin? 
Because  when  this  weight  is  reached  it  is  known 
that  the  water  is  driven  off  and  the  reaction  is 
complete. 

Why  should  glycerite  of  boroglycerin  not  be 
poured  into  bottles  containing  even  a  httle  rinsing 
water?  Water  combines  with  boroglycerin^  forming 
glycerin  and  boric  acid. 

INFUSIONS. 

Why  is  an  infusion  of  a  drug  sometimes  active 
when  the  decoction  of  the  same  drug  is  inert?  The 
heat  necessary  in  making  the  decoction  destroys  or 
volatihzes  the  active  principle. 

Why  is  it  not  admissible  to  make  an  infusion  by 
diluting  a  fluid  extract?  A  fluid  extract,  being 
made  with  an  alcoholic  menstruum,  does  not  contain 
the  same  active  principles  that  would  be  extracted 
by  water  in  making  the  infusion. 

Why  are  infusions  generally  incompatible  with 
metalhc  and  alkaloid  salts?  Because  they  contain 
tannic  acid. 

Why  is  either  rain  or  distilled  water  better  than 
hard  water  in  maJjing  infusions?    Because  they  do 


PREPARATIONS.  27 

not  contain  saline  salts  that  sometimes  cause  precipi- 
tation. 

Why  are  earthen  vessels  best  for  making  infusions? 
They  are  less  hkely  to  be  broken  by  the  heat,  and 
they  retain  heat  longer  than  most  other  vessels. 

Why  should  infusions  not  be  macerated  too  long? 
Tannin  and  other  objectionable  matter  will  be  taken 
out  to  a  greater  extent. 

Why  is  aromatic  sulphuric  acid  used  in  making 
the  infusion  of  cinchona,  1890?  The  acid  converts 
the  alkaloids  into  soluble  sulphates,  and  the  aromatics 
make  the  preparation  more  palatable. 

Why  is  alcohol  used  in  infusion  of  digitaUs?  As 
a  preservative. 

Why  must  cold  water  be  used  in  making  infusion 
of  wild  cherry?  Hot  water  would  coagulate  the 
ferment,  preventing  the  formation  of  the  essential 
oil  of  almonds,  and  would  also  volatihze  the  oil 
even  if  formed. 


LINIMENTS. 

Why  does  an  old  rancid  oil  make  a  better  liniment 
when  mixed  with  an  alkali  than  a  fresh  oil?  The 
free  fat  acid  combines  more  readily,  forming  soap 
which  helps  to  suspend  the  remainder  of  the  oil. 
For  the  same  reason  oleic  acid  is  now  one  of  the  in- 
gredients of  ammonia  liniment. 

Why  is  alcohol  used  in  ammonia  liniment?  It  is 
put  in  to  thin  the  liniment  and  prevent  it  from 


28  WHYS    IN    PHARMACY. 

getting   too   thick.     It  will   also   aid   the   chemical 
reaction. 

Why  does  ammonia  liniment  sometimes  become 
solid?  The  ammonia,  acting  on  the  oil,  forms  a 
soap  which  is  the  cause  of  solidification.  In  lime 
liniment  a  solid  soap  of  lime  is  formed. 

Why  is  powdered  or  granulated  soap  preferable 
to  bar  soap  in  making  soap  liniment?  It  is  more 
constant  in  its  amount  of  water.  A  nearly  saturated 
solution  is  wanted,  and  it  would  be  difficult  to  get 
that  with  bar  soap  without  getting  an  excess. 

Why  is  soap  liniment  allowed  to  stand  for  twenty- 
four  hours  before  filtering?  Soap  contains  some 
sodium  palmitate,  which  goes  into  solution  at  first, 
but  which  afterwards  precipitates  and  is  then 
filtered  out. 

Why  does  soap  frequently  precipitate  even  when 
the  directions  are  followed?  The  liniment  is  intended 
to  be  a  nearly  saturated  solution  of  soap;  sometimes, 
however,  an  excess  of  soap  is  unintentionally  put  in 
through  the  fact  that  it  contained  less  water,  and 
this  excess  is  often  precipitated  by  a  change  in 
temperature  or  evaporation  of  alcohol. 

Why,  in  making  chloroform  liniment,  is  there 
sometimes  a  separation  into  two  layers?  This 
separation  is  due  to  the  use  of  an  excess  of  water 
or  a  deficient  amount  of  alcohol  in  making  the 
soap  liniment. 


PREPARATIONS.  29 


SOLUTIONS. 


Why  does  the  U.  S.  P.  recognize  the  solution  of 
arsenic  trioxide  as  solution  of  arsenous  acid?  The 
tri  oxide  combines  with  water  to  form  the  true 
acid. 

Why  is  hydrochloric  acid  used  in  making  solution 
of  arsenous  acid?  It  aids  the  solution  of  the  arsenic 
trioxide  and  does  not  cause  a  chemical  reaction. 

Why  was  solution  of  arsenous  acid  formerly  called 
solution  of  chloride  of  arsenic?  Because  it  was 
thought  that  chemical  reaction  ensued  in  its  manu- 
facture, forming  the  chloride  of  arsenic. 

Why  is  sodium  bicarbonate  used  in  estimating 
arsenous  acid?  Because  the  iodine  reacts  with  ar- 
senous acid  in  an  alkaline  solution  only.  Hydriodic 
acid  is  formed  and  must  be  neutralized. 

Why  should  only  ^translucent  pieces"  of  ammo- 
nium carbonate  be  used  in  making  solution  of  ammo- 
nium acetate?  Because  the  opaque  pieces  contain 
more  ammonium  bicarbonate,  and  the  proportion  of 
acetic  acid  used  would  therefore  have  to  vary  with 
the  amount  of  bicarbonate  present. 

Why  should  solution  of  ammonium  acetate  be 
made  up  fresh  when  wanted?  The  fresh  solution 
contains  some  carbon  dioxide  which  makes  the  prepa- 
ration more  palatable,  and  this  is  lost  on  keeping 
the  solution. 

Why  must  the  container  for  solution  of  ammonium 


30  WHYS   IN    PHARMACY. 

acetate  be  not  stoppered  at  once?  Because  carbon 
dioxide  is  formed  and  might  exert  sufficient  pressure 
to  burst  the  bottle. 

Why  does  solution  of  ammonium  acetate  some- 
times give  precipitates  with  metallic  and  alkaloid 
salts?  The  solution  is  sometimes  alkaline,  due  to  an 
excess  of  carbonate  or  to  an  insufficient  amount  of 
acid  used. 

Why  does  solution  of  ammonium  acetate,  although 
neutral,  have  a  taste  of  ammonia?  The  loosely 
combined  soda  of  the  saliva  liberates  ammonia. 

Why  is  it  that  the  solution  of  arsenous  and  mer- 
curic iodides  is  clear,  when  the  mercuric  iodide  is 
practically  insoluble  in  water?  Arsenous  iodide  is 
soluble  in  water  and  mercuric  iodide  is  soluble  in 
solutions  of  iodides,  generally  forming  double  com- 
pounds. 

Why  does  Donovan's  solution  change  color  on 
keeping?  Iodine  is  gradually  liberated,  giving  a  red 
color. 

Why,  in  making  lime  water,  is  the  water  rejected 
that  is  put  on  to  the  lime  during  the  first  half 
hour?  Lime  frequently  contains  sodium  carbonate 
and  other  impurities  that  are  soluble  in  water  and 
that  are  not  desired  in  lime  water. 

Why  is  an  excess  of  lime  left  in  the  lime-water 
container?  Lime  water  absorbs  carbon  dioxide  from 
the  air,  forming  calcium  carbonate,  which  is  pre- 
cipitated; an  excess  of  lime  present  keeps  the 
water  saturated  at  all  times. 


rREPARATIONS.  31 

Why  does  heating  a  good  sample  of  clear  lime 
water  produce  a  turbidity?  Because  calcium  hy- 
drate is  less  soluble  in  hot  than  in  cold  water. 

Why  is  the  mixture  of  potassium  chlorate  and 
hydrochloric  acid  warmed  in  a  flask  plugged  with  wet 
cotton  in  making  compound  solution  of  chlorine? 
Heat  aids  chemical  reaction  and  the  formation  of 
chlorine.  The  wetted  cotton  allows  the  air  to  escape 
without  losing  much  chlorine,  the  water  catching  it. 
Water  is  then  passed  through  the  cotton  to  recover 
the  chlorine.  This  formula  is  simpler  than  that  of 
chlorine  water  (1890)  which  it  replaces,  but  it  contains 
other  substances. 

Why  does  the  U.  S.  P.  direct  the  use  of  iron  wire  in 
making  solution  of  ferric  chloride?  Because  it  is 
comparatively  pure  iron. 

Why  is  an  excess  of  iron  used  in  making  solutions  of 
ferric  chloride?  The  reaction  takes  place  more  readily. 

Why  is  the  mixture  of  iron  and  hydrochloric  acid 
heated  before  filtering?  So  as  to  bring  the  reaction 
to  completion,  and  the  salt  into  solution. 

Why  is  hydrochloric  acid  added  to  this  filtrate  of 
ferrous  chloride?  To  prevent  the  formation  of  any 
oxychloride ;  moreover,  hydrochloric  acid  is  necessary 
when  the  ferrous  salt  is  changed  to  ferric,  since  ferric 
chloride  contains  a  larger  proportion  of  chlorine  which 
must  be  gotten  from  the  hydrochloric  acid. 

Why  is  nitric  acid  used  in  making  solution  of  ferric 
chloride?    It  oxidizes  the  ferrous  to  ferric  chloride. 

Why  is  hydrochloric  acid  added  to  the  solution  of 


32  WHYS   IN    PHARMACY. 

ferric  chloride  just  before  making  up  to  the  required 
amount  with  water?  Nearly  all  the  free  hydro- 
chloric acid  is  driven  off  in  getting  rid  of  the  nitric 
acid;  and  if  an  excess  of  hydrochloric  acid  is  not 
present,  oxychloride  of  iron  is  precipitated  on  allow- 
ing the  solution  to  stand. 

Why  is  a  part  of  ferric  chloride  converted  into  ferric 
hydroxide,  and  this  dissolved  in  the  remaining 
solution  of  ferric  chloride,  in  making  solution  of 
dialyzed  iron?  The  solution  so  obtained  contains 
basic  ferric  chloride;  this  does  not  pass  through  the 
filter  as  does  ferric  chloride. 

Why  should  the  solution  of  ammonium  acetate 
''not  be  alkaline"  in  making  solution  of  iron  and 
ammonium  acetate?  Because  iron  would  be  pre- 
cipitated as  a  basic  salt. 

Why  is  nitric  acid  used  in  making  solution  of  ferric 
subsulphate?     It  oxidizes  the  ferrous  to  ferric  iron. 

Why  is  sulphuric  acid  used  in  making  Monsel's 
solution?  Because  iron  in  the  ferric  condition  has  a 
larger  proportion  of  sulphuric  acid  than  it  has  in 
the  ferrous  state. 

Why  is  the  ferrous  sulphate  added  in  portions  to 
the  mixture  of  sulphuric  and  nitric  acids  in  making 
Monsel's  solution?  Because,  if  added  all  at  once 
the  amount  of  nitric  oxide  gas  formed  would  be 
sufficient  to  cause  the  expulsion  of  some  of  the  liquid. 

Why,  in  making  MonseFs  solution,  is  more  nitric 
acid  added  if,  on  adding  a  few  drops,  red  fumes  are 
given  off?    The  formation  of  red  fumes  shows  that 


PREPARATIONS.  33 

all  of  the  ferrous  sulphate  has  not  been  changed  to  the 
ferric  compound  and  so  more  nitric  acid  is  necessary. 

Why,  in  making  MonseFs  solution,  does  the  liquid 
become  almost  black,  and  then  lighter  on  further 
heating?  Some  of  the  nitric  oxide  combines  with  the 
ferrous  sulphate,  forming  this  dark  compound,  which 
is  afterwards  decomposed  by  the  heat. 

Why  does  MonseFs  solution  separate  a  solid  when 
mixed  with  one  half  its  volume  of  sulphuric  acid, 
while  solution  of  ferric  sulphate  does  not?  Because, 
in  the  concentrated  MonseFs  solution,  the  ferric  sul- 
phate is  not  soluble  in  the  sulphuric  acid,  MonseFs 
solution  being  stronger  than  the  solution  of  the 
sulphate  of  iron. 

Why  should  the  solution  of  ferric  subsulphate  be 
kept  in  a  moderately  warm  place  protected  from 
Hght?  When  chilled  it  solidifies  and  light  reduces 
it. 

Why  is  solution  of  mercuric  nitrate  made  from  the 
red  oxide?  The  solution  is  more  easily  made  from 
it  than  from  the  metallic  mercury. 

Why  is  potassium  iodide  used  in  making  com- 
pound solution  of  iodine?  Iodine  is  nearly  insoluble 
in  water,  but  readily  soluble  in  an  aqueous  solution 
of  an  iodide. 

Why  does  solution  of  magnesium  citrate  some- 
times precipitate  on  keeping?  The  normal  magne- 
sium citrate  is  less  soluble  than  the  acid  citrate  and 
when  the  excess  of  citric  acid  is  neutralized  the 
magnesium  citrate  is  precipitated. 


34  WHYS    IN   PHARMACY. 

Why  is  the  carbon  dioxide,  liberated  by  the  action 
of  citric  acid  on  magnesium  carbonate,  not  utiHzed 
in  carbonating  the  solution  of  magnesium  citrate, 
instead  of  putting  in  potassuim  bicarbonate?  The 
amount  of  carbon  dioxide  from  the  magnesium 
carbonate  is  too  great  to  use  all  of  it  and  it  would 
be  difficult  to  regulate. 

Why  should  bottles  of  magnesium  citrate  solution, 
and  other  bottles  containing  water  and  gas  under 
pressure,  be  kept  on  their  sides?  To  keep  the 
stoppers  wet  and  swollen  so  as  to  prevent  the 
escape  of  gas. 

Why  should  distilled  water  that  has  been  recently 
boiled  always  be  used  in  making  solution  of  lead 
subacetate?  Because  ordinary  water  is  apt  to  contain 
some  non-volatile  substances  that  would  precipitate 
the  lead,  and  distilled  water,  unless  recently  boiled, 
will  contain  some  carbon  dioxide  and  oxygen  ab- 
sorbed from  the  air,  which  will  also  precipitate  the 
lead. 

Why  is  there  a  white  residue  left  after  boiling 
lead  acetate  and  lead  oxide  together  with  water? 
Because  there  is  formed  a  basic,  insoluble  lead 
acetate  besides  the  compound  that  goes  into  solu- 
tion. 

Why  does  a  solution  of  lead  subacetate  always 
deposit  a  white  solid  on  exposure  to  air?  It  absorbs 
carbon  dioxide  and  forms  lead  carbonate. 

Why  is  compound  tincture  of  lavender  used  in 
Fowler's  solution?    It  gives  flavor  and  color. 


PREPARATIONS.  35 

Why  is  it  advised  to  not  keep  Fowler's  solution 
longer  than  a  year?  It  is  said  to  be  slowly  oxidized 
to  an  arsenate  which  is  less  active. 

Why  should  solution  of  potassium  citrate  be 
made  up  fresh?  It  loses  its  carbon  dioxide  and 
soon  spoils. 

Why  should  solution  of  chlorinated  soda  be  kept 
in  glass-stoppered  bottles  protected  from  the  light? 
Chlorine  attacks  ordinary  cork  stoppers,  and  light 
tends  to  decompose  the  hypochlorite. 

Why  is  potassium  bicarbonate  used  in  preference 
to  potassium  carbonate  in  making  solution  of  potas- 
sium hydroxide  (1890)?     Because  it  is  purer. 

Why  is  potassium  bicarbonate  in  solution  boiled 
until  effervescence  ceases  in  making  solution  of 
potassium  hydroxide  (1890)?  So  as  to  convert  it 
into  potassium  carbonate,  which  reacts  better, 
calcium  acid  carbonate  being  somewhat  soluble. 

Why  are  the  mixture  of  lime  and  water  and  the 
solution  of  potassium  carbonate  heated  before 
mixing?  If  mixed  while  hot  the  calcium  carbonate 
is  precipitated  in  a  denser  form  and  will  settle 
more  quickly. 

Why  is  the  solution  separated  from  the  insoluble 
matter  by  decantation  or  siphoning,  rather  than  by 
filtration?  In  filtering  through  paper  the  alkali 
attacks  the  paper. 

Why  are  6.0  grams  of  potassium  hydroxide  used 
in  making  100  grams  of  a  five  per  cent,  solution? 
Potassium    hydroxide    generally    contains   moisture 


36  WHYS   IN   PHARMACY. 

and  carbon  dioxide,  the  U.  S.  P.  allowing  as  much 
as  fifteen  per  cent,  of  impurities,  and  allowance  is 
made  for  these  in  making  the  solution. 

Why  must  solution  of  potassium  hydroxide  be 
protected  from  the  air?  It  absorbs  carbon  dioxide 
readily. 

Why  should  solution  of  potassium  hydroxide  be 
kept  in  green  glass  bottles  rather  than  in  flint? 
Potassium  hydroxide  dissolves  green  glass  less 
readily. 

Why  does  Labarraque's  solution  effervesce  when 
an  acid  is  added  to  it?  An  excess  of  sodium  car- 
bonate is  generally  present,  and  an  acid  liberates 
carbon  dioxide.     Chlorine  is  also  liberated. 

AVliy  is  nitric  acid  used  in  making  solution  of 
zinc  chloride?  Zinc  frequently  contains  iron  as  an 
impurity.  This  is  dissolved  by  hydrochloric  acid, 
forming  ferrous  chloride,  and  nitric  acid  converts 
it  into  a  ferric  compound  so  that  it  may  be  more 
completely  precipitated.  Ferrous  salts  are  not  com- 
pletely precipitated  by  hydrates  or  carbonates. 

Why  is  the  solution  of  zinc  chloride  evaporated 
and  fused?     To  get  rid  of  the  nitric  acid. 

Why  should  the  temperature  of  fusion  be  below 
115°  C?  So  as  to  avoid  volatilization  and  decom- 
position of  the  zinc  chloride. 

Why  is  zinc  carbonate  used  in  making  solution 
of  zinc  chloride?  It  precipitates  the  iron  as  the 
hydroxide,  and,  being  insoluble,  the  excess  can  be 
filtered  out;    no  impurity  is  therefore  introduced. 


PREPARATIONS.  37 

Why  is  solution  of  zinc  chloride  separated  by 
decantation  instead  of  by  filtration?  The  con- 
centrated solution,  being  caustic,  would  attack 
filter  paper. 

Why  is  ammonia  used  in  solution  of  carmin,  N.  F.  ? 
Ammonia  forms  a  soluble  compound  with  carmin. 

Why  is  iron  and  ammonium  sulphate  used  in 
making  solution  of  hypophosphite  of  iron,  N.  F.? 
It  is  nearly  neutral  and  the  iron  hypophosphite  is 
more  completely  precipitated. 

Why  is  potassium  citrate  used  in  making  solution 
of  hypophosphite  of  iron,  N.  F.?  The  potassium 
citrate  makes  the  hypophosphite  soluble  in  water, 
perhaps  by  forming  a  double  compound. 

Why  is  diluted  hypophosphorous  acid  used  in 
solutions  of  ferrous  iodide  and  ferrous  chloride, 
N.  F.?  It  retards  or  prevents  oxidation  of  the 
ferrous  salts  to  the  ferric  condition. 

Why  is  lead  carbonate  preferred  in  clarifying  the 
solution  of  gutta-percha,  N.  F.?  Because  it  is  heavy 
and  will  settle  to  the  bottom  notwithstanding  the 
solution  is  very  viscid. 

Why  is  sodium  bicarbonate  used  in  pancreatic 
solution,  N.  F.?  To  make  the  solution  alkaline. 
Pancreatin   acts  best  in  alkaline   fluids. 

Why  is  talcum  used  in  preference  to  calcium 
phosphate  in  filtering  aromatic  solution  of  pepsin, 
N.  F.?  This  solution  contains  hydrochloric  acid 
which  would  dissolve  the  phosphate,  but  does  not 
act  on  talcum. 


38  WHYS    IN   PHARMACY. 

Why  is  sodium  bicarbonate  used  in  making  solu* 
tion  of  saccharin,  N.  F.?  To  make  the  saccharin 
soluble. 

Why  is  it  that  the  N.  F.  directs  one  gram  of 
sodium  arsenate  to  600  cubic  centimeters  of  water 
in  making  Pearson's  solution,  and  then  states  that 
the  solution  is  one  tenth  as  strong  as  the  U.  S.  P. 
solution,  which  is  one  per  cent,  in  strength?  The 
U.  S.  P.  directs  the  use  of  the  anhydrous  salt,  whereas 
the  N.  F.  uses  the  crystallized,  which  has  seven 
molecules  of  water  of  crystaUizatJon. 

Why  is  carbon  dioxide  evolved  in  DobelFs  solu- 
tion, since  carbolic  acid  does  not  decompose  sodium 
bicarbonate?  Glycerin  decomposes  the  borax,  form- 
ing glycerol  borate  and  sodium  metaborate;  water 
decomposes  this  glycerol  borate,  forming  glycerin 
and  boric  acid,  and  the  boric  acid  liberates  carbon 
dioxide  from  the  bicarbonate. 

Why  is  the  soluble  essence  of  ginger,  N.  F.,  clas- 
sified with  solutions?  Possibly  because  it  does  not 
contain  much  alcohol,  although  it  has  nearly  as 
much  as  the  soluble  tincture  of  Tolu. 

MASSES. 

Why  is  boiling  distilled  water  used  to  dissolve  the 
ferrous  sulphate  in  making  mass  of  carbonate  of 
iron?  It  is  free  from  oxygen  and  so  will  not  oxidize 
the  ferrous  salt  to  the  ferric  condition. 

Why  is  the  solution  of  ferrous  sulphate  added  to 


PREPARATIONS.  39 

the  solution  of  carbonate  and  not  the  carbonate 
to  the  iron?  By  adding  the  carbonate  to  the  iron, 
there  would  be  more  danger  of  getting  a  basic 
instead  of  a  normal  carbonate  of  iron. 

Why  is  the  bottle  filled  with  water  before  putting 
aside  for  settling?  In  order  to  exclude  the  air  as 
far  as  possible  to  prevent  oxidation. 

Why  is  syrup  added  to  the  solution  of  ferrous 
sulphate  in  making  mass  of  iron?  Sugar  prevents 
or  retards  the  oxidation  of  the  ferrous  salt. 

Why  is  the  washing  of  ferrous  carbonate  by  de- 
cantation  preferable  to  washing  on  a  filter?  There  is 
less  exposure  to  the  oxygen  of  the  air. 

Why  does  mass  of  carbonate  of  iron  sometimes 
become  brown  on  keeping?  It  oxidizes  to  ferric  oxide 
which  is  brown. 

Why  is  it  that  carbonate  of  iron  thus  prepared 
has  a  green  color  when  pure  ferrous  carbonate  is 
white?  Because  all  the  commercial  ferrous  carbonate 
contains  some  ferric  salt,  and  this  green  product  is  a 
combination  of  ferrous  and  ferric  iron. 

Why  are  honey  and  glycerin  good  for  extin- 
guishing mercury?  Because  they  are  viscid  and  keep 
the  globules  of  mercury  apart. 

Why  is  mass  of  mercury  called  '^blue  mass?" 
Mercury  in  a  very  fine  state  of  subdivision  has  a 
bluish  color. 

Why  is  w^ater  used  in  making  mass  of  copaiba 
(1890)  ?     It  aids  the  chemical  reaction. 

Why  is  it  that  copaiba  solidifies  with  such  a  small 


40  WHYS    IN    PHARMACY. 

amount  of  magnesia?  The  magnesia  combines  with 
the  resin,  forming  a  bulky  resin  soap  that  sohdifies 
the  oil  Magnesia  employed  with  the  oil  of  copaiba 
does  not  cause  solidification. 

Why  should  care  be  used  in  choosing  copaiba  for 
making  mass  or  pills  of  copaiba?  Copaiba  varies  in 
viscosity  and  composition,  and  the  thickest  contain- 
ing the  most  resin  is  the  best. 


MIXTURES. 

Why  should  chalk  mixture  be  made  when  wanted? 
It  quickly  becomes  sour  upon  keeping,  and  the  acid 
formed  liberates  carbon  dioxide. 

Why  is  sugar  used  in  compound  iron  mixture?  To 
prevent  or  retard  the  oxidation  of  the  ferrous  car- 
bonate. 

Why  does  compound  iron  mixture  turn  brown  on 
keeping?  The  green  ferroso-ferric  carbonate  oxi- 
dizes to  red-brown  ferric  oxide. 

Why  is  it  better  to  make  a  concentrated  aqueous 
solution  of  chloral  hydrate  and  dissolve  the  extracts 
in  this  rather  than  to  follow  the  N.  F.  directions  in 
making  the  compound  mixture  of  chloral  and  potas- 
sium bromide?  Less  of  the  resinous  matter  is  sub- 
sequently precipitated.  A  strong  solution  of  chloral 
hydrate  is  a  good  solvent  for  resins. 


PREPARATIONS.  41 

MUCILAGES. 

Why  is  mucilage  of  acacia  of  but  little  service  as  a 
suspending  agent  when  alcohol  is  present  in  large 
proportions?  Acacia  is  insoluble  in  alcohol;  it  is 
thrown  out  of  aqueous  solution  by  it,  and  the 
emulsion  is  broken  up. 

Why  is  powdered  acacia  -harder  to  dissolve  in  water 
than  the  granulated?  In  the  preparation  for  granu- 
lation, acacia  loses  about  two  per  cent,  of  moisture, 
but  in  getting  it  dry  enough  to  powder  it  loses  about 
ten  per  cent,  of  moisture.  Moreover,  powdered 
acacia  makes  masses  with  water  which  are  hard 
to  rub  out. 

Why  is  lime  water  used  in  mucilage  of  acacia? 
It  neutralizes  acidity  and  tends  to  prevent  decom- 
position. 

Why  is  it  better  to  add  only  a  small  amount  of 
water  at  first  in  making  mucilage  of  acacia  from  the 
powdered  acacia?  The  lumps  that  always  form  can 
be  rubbed  out  much  more  easily  and  quickly. 

Why  is  mucilage  of  tragacanth  better  than  acacia 
as  a  suspending  agent  when  ferric  salts  or  borax 
are  present?    It  is  not  coagulated  by  these. 

Why  does  it  take  a  smaller  amount  of  tragacanth 
than  acacia  to  act  as  an  emulsifying  or  suspending 
agent?  Only  a  portion  of  tragacanth  is  soluble  in 
water,  and  that  which  does  not  dissolve  swells  and 
in  so  doing  takes  up  a  large  amount  of  water  before 
it  makes  a  thin  mixture. 


42  WHYS    IN   PHARMACY. 

Why  is  chondrus,  washed  with  water  before 
making  it  into  a  mucilage?  To  free  it  from  salt 
and  foreign  matter. 

OLEATES. 

Why  are  oleates  of  the  metals  preferably  made 
by  double  decomposition?  Because  oleic  acid  com- 
bines slowly  with  a  metallic  oxide  or  hydroxide. 

Why  is  the  oleate  of  mercury  best  made  without 
heat?  If  even  a  little  heat  is  used  the  oleate  decom- 
poses much  more  quickly,  ultimately  precipitating 
metallic  mercury. 

Why  is  it  generally  necessary  to  add  acetic  acid  to 
clear  a  mixture  of  lead  acetate  and  water  in  making 
oleate  of  lead,  N.  F.?  Lead  acetate  contains  a  Httle 
lead  carbonate,  which  is  insoluble  in  water,  but  which 
is  converted  into  the  acetate  by  the  acid. 

Why  must  a  large  excess  of  acetic  acid  be  avoided 
in  making  oleate  of  lead,  N.  F.?  Acetic  acid  would 
liberate  oleic  acid  from  sodium  oleate,  making  the 
oleate  soft  and  sticky. 

Why  is  it  necessary  to  add  some  acetic  acid  to  the 
solution  of  soap  in  making  lead  oleate?  Soap  is 
sometimes  strongly  alkahne,  and  the  lead  would  be 
precipitated  as  the  hydroxide  or  carbonate  instead 
of  the  oleate. 

Why  is  boihng  water  used  in  washing  lead  oleate? 
The  heat  softens  or  liquefies  the  oleate  and  thus  gives 
the  water  a  better  chance  to  dissolve  out  the  sodium 
acetate. 


PREPARATIONS.  43 

Why  is  the  free  alkaloid  used  in  making  an  oleate 
of  an  alkaloid?  The  oleic  acid  combines  with  it  to 
form  a  compound  soluble  in  the  acid.  Alcohol  is 
used  to  dissolve  the  alkaloid  and  aid  reaction.  The 
ordinary  alkaloidal  salts  do  not  dissolve  in  oleic 
acid  or  olive  oil. 

Why  are  metallic  oleates  best  made  of  normal 
strength?    They  keep  better. 

OLEORESINS. 

Why  is  acetone  used  in  place  of  ether  in  making 
oleoresins?  It  is  not  so  volatile  or  inflammable  and 
is  a  good  solvent  for  oils  and  resins,  combining  the 
solvent  properties  of  alcohol  and  ether. 

Why  should  the  oleoresin  of  male  fern  be  stirred 
up  before  taking  any  out  of  the  container?  Filicic 
acid,  the  active  principle,  separates  on  standing. 

Why  should  capsicum  not  be  percolated  to  exhaus- 
tion in  making  oleoresin  of  capsicum?  The  last 
part  of  the  percolation  removes  a  large  proportion 
of  inert  fatty  matter  and  but  a  small  proportion 
of  active  matter. 

Why  should  oleoresin  of  cubebs  be  decanted? 
Inert  cubebin  settles  out  on  standing. 

Why  is  lupuHn  ''very  lightly"  pressed  in  making 
the  oleoresin?  It  yields  so  much  soluble  matter 
that  the  acetone  solution  would  not  be  able  to 
pass  through  the  drug. 


44  WHYS   IN    PHARMACY. 

OILS. 

Why  do  fixed  oils  vary  in  color?  On  account  of 
oxidation  products  and  the  presence  of  other  foreign 
matter,  such  as  chlorophyll. 

Why  do  the  melting-points  of  different  samples 
of  the  same  kind  of  fat  vary?  The  melting-point 
generally  varies  with  the  proportion  of  olein  and 
stearin,  and  this  varies  with  the  season  of  the  year 
and  with  the  process  of  obtaining  the  fat.  On 
account  of  this  variation  the  determination  of  the 
melting-point  is  of  but  little  value  in  testing  for 
adulterations. 

Why  do  non-drying  oils  undergo  decomposition? 
Some  authorities  say  that  rancidity  is  due  to  the 
action  of  ferments  liberating  the  free  fat  acids,  and 
others  say  that  rancidity  results  from  the  direct 
oxidation  of  the  fat  by  oxygen  and  light  acting 
simultaneously. 

Why  is  the  determination  of  the  specific  gravity 
of  but  little  value  in  determining  the  identity  or 
adulteration  of  an  oil  or  fat?  The  specific  gravity 
varies  with  the  process  of  obtaining  the  fat,  the  proc- 
ess of  purifying  it,  the  presence  of  free  fat  acids,  the 
age,  the  amount  of  oxidation,  and  the  temperature. 

Why  is  mercuric  chloride  used  with  iodine  in 
making  the  iodine  absorption  tests  for  oils?  Iodine 
reacts  only  slowly  with  a  fixed  oil  at  ordinary  tem- 
perature, but  much  more  readily  in  the  presence 
of  corrosive    sublimate. 


PREPARATIONS.  45 

Why  is  a  little  heat  generally  used  in  obtaining 
fixed  oils  from  seeds  by  pressure?  Heat  renders 
the  oil  less  viscid  and  a  larger  yield  is  obtained, 
but  the  quality  is  generally  not  so  good. 

Why  is  winter-pressed  lard  oil  preferable  to 
summer-pressed?  It  contains  less  stearin  than  the 
summer-pressed  product,  and  therefore  remains  liquid 
at  a  lower  temperature. 

Why  is  most  of  the  expressed  oil  of  almond 
obtained  from  the  bitter  almonds  and  not  from 
the  sweet?  Although  the  bitter  almonds  contain 
less  fixed  oil  than  the  sweet,  they  are  cheaper,  and 
the  cake  left  from  the  fixed  oil  may  be  used  for 
obtaining  the  volatile  oil. 

Why  is  sodium  hydroxide  sometimes  used  in 
purifying  cottonseed  oil?  It  converts  a  small  amount 
of  fat  into  soap,  which  on  settling  carries  much  of 
the  coloring  matter  with  it. 

Why  is  so  much  cottonseed  oil  shipped  to  Mediter- 
ranean ports?  Much  of  the  olive  oil  comes  from 
these  ports,  and  cottonseed  oil  is  used  as  an  adulter- 
ant or  substitute  for  olive  oil. 

Why  should  the  linseed  oil  used  in  pharmacy  be 
obtained  by  cold  pressure?  It  is  less  acrid  and  not 
so  highly  colored. 

Why  is  cod  liver  oil  used  more  than  other  oils 
as  a  nutrient?  It  is  more  readily  absorbed  and 
assimilated,  but  why  it  is  more  readily  absorbed  is 
a  question  that  has  not  been  decided.  Some  say 
that  it  is  because  the  oil  contains  biliary  principles: 


46  WHYS  IN   PHARMACY. 

others  think  that  it  is  because  the  presence  of  free 
fat  acids  facihtates  emulsification. 

Why  can  the  silver  nitrate  test  not  be  depended 
upon  for  the  detection  of  cottonseed  oil  in  olive  oil? 
Cottonseed  oil  can  be  so  purified  that  it  will  not 
give  the  test. 

Why  is  castor  oil  boiled  with  water  in  purifying 
it?  Boiling  water  takes  out  the  albuminous  matter 
and  destroys  the  small  amount  of  acrid  poisonous 
matter  that  is  removed  with  the  oil. 

Why  is  expressed  oil  of  almonds  heated  to  250° 
C.  in  making  phosphorated  oil  (1890)?  To  remove 
any  air  and  water,  and  to  cause  the  separation  of 
some  organic  matter,  all  of  which  would  tend  to 
oxidize  the  phosphorus  if  they  were  present. 

Why  is  ether  used  in  phosphorated  oil  (1890)? 
It  prevents  oxidation  and  gives  a  more  palatable 
taste. 

Why  are  the  volatile  oils  that  are  obtained  by 
distillation  usually  distilled  with  water?  They  can 
be  distilled  at  a  lower  temperature  and  with  less 
resulting  decomposition.  The  organic  matter  from 
which  oil  is  obtained  yields  less  of  the  empyreumatic 
substances. 

Why  is  the  '^enfleurage'^  method  frequently 
resorted  to  in  obtaining  oils?  The  method  of 
extracting  the  oil  by  a  neutral  fat  is  used  when 
the  oil  is  present  in  small  quantities  and  when  it 
is  decomposed  by  heat. 

Why  should  volatile  oils  be  protected  from  light 


PREPARATIONS.  47 

and  air  since  they  do  not  become  rancid?  Light 
and  air  cause  an  oxidation  of  the  oil  and  a  destruc- 
tion of  the  characteristic  odor.  Ozone  is  developed 
by  some  oils. 

Why  do  volatile  oils,  when  dropped  on  paper,  some- 
times leave  a  stain  which  is  not  dissipated  by  heat? 
The  stain  is  due  to  resinous  matter,  usually  formed 
by  oxidation.  The  stain  can  be  distinguished  from 
that  of  a  fixed  oil  by  the  fact  that  it  dissolves  in 
alcohol. 

Why  is  salt  water  used  in  distilling  some  oils, 
such  as  oil  of  cloves?  Salt  raises  the  boiling-point 
of  water,  bringing  it  nearer  that  of  the  oil,  and  is 
used  when  the  oil  has  a  high  boiling-point. 

Why  are  bitter  almonds  macerated  with  water 
for  several  hours  before  distilling?  In  order  to 
allow  the  ferment  to  act  on  the  amygdalin,  forming 
the  oil.     Water  is  necessary  for  this  reaction. 

Why  does  oil  of  bitter  almonds  sometimes  solidify 
on  keeping?  The  oil  consists  chiefly  of  benzaldehyde 
which  oxidizes,  forming  benzoic  acid. 

Why  does  the  oil  obtained  from  bitter  almonds 
keep  better  than  the  synthetic  oil  of  bitter  almonds? 
It  is  claimed  by  some  that  in  the  natural  oil  the 
hydrocyanic  acid  is  combined  with  the  benzaldehyde, 
keeping  it  from  being  so  easily  oxidized. 

Why  is  it  customary  to  dry  oil  of  bitter  almonds 
over  calcium  chloride?  If  moisture  is  left  in  it 
tends  to  aid  oxidation  of  the  oil. 

Why  is  synthetic  oil  of  bitter  almonds  not  good 


48  WHYS   IN   PHARMACY. 

for  the  finer  perfumes?  It  often  contains  chlorinated 
compounds  which  possess  unpleasant  odors. 

Why  does  oil  of  cassia  become  acid?  It  consists 
largely  of  cinnamic  aldehyde  which  is  slowly  oxidized 
to  cinnamic  acid. 

Why  do  oils  of  eucalyptus,  cajuput,  and  rosemary 
resemble  one  another  in  odor?  They  contain  euca- 
lyptol  (cineol). 

Why  are  green  juniper  berries  used  for  obtaining 
oil  of  juniper?  They  yield  more  oil  than  when 
fully  ripe. 

Why  does  oil  of  cajuput  have  a  green  color?  When 
first  distilled  it  contains  some  chlorophyll,  but  after 
rectification  it  is  colorless.  If  the  colorless  oil  is 
allowed  to  stand  in  copper  containers  it  becomes 
green,  due  to  the  solution  of  a  little  copper.  This 
copper  cannot  be  detected  by  ammonia,  as  ammonia 
does  not  give  the  characteristic  blue  color. 

Why  is  benzin  used  in  estimating  cineol  in  oil  of 
cajuput?  It  dissolves  the  other  constituents  of  the 
oil  but  not  the  cineol  phosphate  that  is  formed  when 
phosphoric  acid  is  added. 

Why  is  potassium  hydroxide  used  in  estimating 
eugenol  in  oil  of  cloves?  It  combines  with  eugecol 
to  form  a  soluble  compound,  the  other  constituents 
not  combining  do  not  dissolve  in  the  water. 

Why  is  oil  of  lemon  obtained  by  expression  rather 
than  by  distillation?  The  flavor  is  finer  when 
obtained  by  expression. 

Why  should  about  five  per  cent,   of  alcohol  be 


PEEPARATIONS.  49 

added  to  oils  of  lemon,  orange,  and  bergamot  as  soon 
as  the  retailer  opens  the  containers?  These  oils 
change  very  quickly,  acquiring  a  turpentine  odor  and 
taste.     Alcohol  preserves  them. 

Why  do  different  oils  of  peppermint  vary  in  their 
solidifying  points?  The  solidification  depends  on  the 
proportion  of  menthol  present  and  this  varies  with 
the  oil. 

Why  does  oil  of  patchouly  have  a  musty  odor? 
Before  the  leaves  are  distilled  they  are  piled  in  heaps 
and  allowed  to  undergo  some  degree  of  decomposi- 
tion. 

Why  is  oil  of  pimenta  distilled  from  the  unripe 
fruit?    The  ripe  fruit  is  nearly  odorless. 

Why  do  oils  of  pimenta,  cloves,  and  bay  have  a 
somewhat  similar  odor?  They  all  contain  a  large 
proportion  of  eugenol,  to  which  the  odor  of  the  oils 
is  largely  due. 

Why  is  oil  of  rose  solid  in  cool  weather?  It  con- 
tains a  hydrocarbon  which  has  a  comparatively  high 
liquefying-point.  This  hydrocarbon  is  not  the  odor- 
ous principle,  although  its  presence  is  taken  as  an 
indication  of  the  purity  of  the  oil. 

Why  is  Indian  oil  of  sandalwood  darker  than  that 
distilled  in  Europe?  In  India  the  distillation  is  pro- 
longed and  causes  the  formation  of  decomposition 
products. 

Why  are  sandalwood  trees  left  on  the  ground  some 
months  before  distilling?  The  ants  eat  off  the  sap- 
wood,  leaving  the  heart-wood  which  yields  the  oil. 


50  WHYS   IN    PHARMACY. 

Why  is  black  mustard  macerated  with  water  for 
some  time  before  distiUing  the  volatile  oil?  In  order 
to  allow  the  ferment  to  act  on  the  glucoside  sinigrin, 
forming  the  oil. 

Why  does  oil  of  turpentine  become  acid?  It  slowly 
resinifies,  forming  abietic  anhydride  which  is  acid  to 
litmus  when  dissolved  in  alcohol.  Other  acids,  such 
as  formic,  acetic,  and  carbonic,  are  probably  also 
formed. 

Why  is  sodium  hydroxide  used  in  rectifying  oil  of 
turpentine?  It  neutralizes  any  acid  and  renders  it, 
as  well  as  the  resin,  less  volatile. 

Why  is  old  oil  of  turpentine  used  in  poisoning  by 
phosphorus?  It  contains  ozone  which  perhaps  oxi- 
dizes the  phosphorus  to  less  poisonous  products. 

Why  is  oil  of  vetivert  used  in  perfumery?  On  ac- 
count of  its  sparing  volatihty  it  gives  lasting  proper- 
ties to  the  perfume. 


PILLS. 

Why  is  the  maximum  weight  of  pills  of  organic 
matter  about  five  grains,  while  that  of  pills  of 
inorganic  matter  can  be  as  high  as  nine  or  ten 
grains?  The  size  sometimes  governs  the  possible 
weight  of  a  pill,  and  inorganic  matter  is  usually  less 
bulky  than  organic  matter. 

Why  is  it  best  to  triturate  potent  substances  with 
sugar  of  milk  or  other  inert  substance  before  mixing 


rREPARATIONS.  51 

them  with  the  other  ingredients  of  the  pill  mass?  By 
so  doing  the  potent  substance  is  more  thoroughly 
distributed  throughout  the  mass. 

Why  is  a  mortar  and  pestle  better  than  a  pill-tile 
and  spatula  in  making  a  pill  mass?  More  pressure 
can  be  used  in  mixing  the  ingredients,  the  heat  gen- 
erated softens  the  mass,  and  there  is  less  danger  of 
getting  in  too  much  excipient. 

Why  are  simple  syrup,  syxup  of  acacia,  mucilage 
of  acacia,  and  glucose  objectionable  as  general  pill 
excipients?  Pills  made  with  any  one  of  them  soon 
become  so  hard  that  they  pass  through  the  ahmentary 
canal  without  dissolving.  The  addition  of  a  Uttle 
glycerin  which  is  hygroscopic  overcomes  this  objec- 
tion. 

Why  is  glycerin  objectionable  as  a  pill  excipient 
when  used  alone?  It  is  hygroscopic,  and  pills  made 
with  it  may  absorb  moisture  and  become  too  soft. 

Why  is  soap  a  good  excipient  for  resinous  sub- 
stances? It  not  only  makes  a  good  mass,  but  prob- 
ably aids  the  emulsification  and  absorption  of  the 
resin  in  the  alimentary  canal. 

Why  is  sulphuric  acid  sometimes  used  in  pills  of 
quinine?  It  reduces  the  bulk  by  converting  the 
quinine  into  the  bisulphate. 

Why  should  soap  not  be  used  with  metallic  salts? 
It  combines  with  many  of  them,  forming  oleates  or 
hydroxides  if  strongly  alkaline. 

Why  should  tragacanth  be  used  only  in  small 
amounts  as  a  pill  excipient?    If  used  in  large  quan- 


52  WHYS   IN   PHARMACY. 

titles  it  makes  the  mass  so  spongy  that  the  pills  are 
made  with  great  difficulty. 

Why  cannot  potassium  permanganate,  silver  ni- 
trate, and  gold  chloride  be  massed  with  common 
excipients?  Because  they  are  reduced.  Some  sub- 
stance that  will  not  be  acted  upon  must  be  used. 

Why  are  fibrous  drugs  frequently  useful  as  pill 
excipients?  They  are  absorbents  and  serve  to  bind 
the  mass  together,  as  well  as  to  aid  disintegration  of 
the  pill. 

Why  should  althsea  and  tragacanth  be  used  spar- 
ingly as  pill  excipients?  They  contain  mucilage  and 
are  apt  to  make  the  pills  hard.  They  also  make  the 
pill  mass  spongy  and  difficult  to  roll. 

Why  is  lycopodium  a  good  dusting  powder?  It 
is  a  fine  powder,  tasteless,  repels  water,  and  does 
not  become  sticky;    moreover,  it  protects  the  pill. 

Why  is  arrowroot  or  potato-starch  better  than 
corn-starch  as  a  dusting  powder?  Corn-starch  tends 
to  stick  together  more  than  either  of  the  other  two. 

Why  must  pills  be  kept  in  motion  after  being 
dipped  in  a  hot  solution  of  gelatin  to  coat  them? 
If  they  were  not  kept  in  motion  the  coating  would 
run  to  the  lower  side  of  the  pill,  forming  a  lump. 

Why  should  glycerin  not  be  used  as  a  part  of  the 
pill  excipient  if  the  pill  is  to  be  coated  with  gelatin? 
Glycerin  does  not  dry  out  and  it  dissolves  the  gelatin. 

Why  may  either  keratin  or  salol  be  used  in  coating 
pills  when  it  is  desired  that  the  pill  should  not  dis- 
solve in  the  stomach?     Both   of   these  substances 


PREPARATIONS.  53 

do  not  dissolve  in  the  acid  contents  of  the  gastric 
juice,  but  do  in  the  alkahne  fluids  of  the  intes- 
tine. 

Why  is  dried  sulphate  of  iron  used  in  preference 
to  the  crystalline  in  making  pills  of  aloes  and 
iron?    The  dried  sulphate  is  less  bulky. 

Why  does  the  mixture  of  salts  with  glycerin  and 
water  in  pills  of  carbonate  of  iron  get  softer  on  tritu- 
rating? It  is  due  to  the  water  of  crystallization 
which  is  liberated  when  the  reaction  takes  place. 

Why  is  the  crystalline  sulphate  of  iron  used  in 
Blaud's  pills  in  preference  to  the  dried  sulphate? 
It  dissolves  more  rapidly  and  consequently  reacts 
more  quickly. 

Why  do  pills  of  carbonate  of  iron  change  color? 
Ferric  oxide  is  formed,  which  gives  them  a  reddish 
color. 

Why  is  reduced  iron  used  in  pills  of  iodide  of 
iron?    It  is  finer  and  reacts  more  readily. 

Why  is  an  excess  of  iron  used  in  pills  of  iodide  of 
iron?  To  prevent  subsequent  liberation  of  iodine 
by  oxidation. 

Why  are  iron  and  iodine  triturated  together  until 
free  from  red  color?  This  shows  that  all  of  the 
iodine  has  united  with  the  iron. 

Why  are  pills  of  iodide  of  iron  coated?  So  as  to 
prevent  oxidation  by  the  air  and  the  liberation  of 
iodine. 

Why  are  pills  of  iodine  best  made  with  starch? 
Starch    forms    a    compound   with   iodine,  which  is 


54  WHYS    IN   PHARMACY. 

easily  broken  up  in  the  alimentary  canal,  giving 
the  action  of  iodine. 

Why  are  pills  of  phosphorus  coated?  To  prevent 
oxidation. 

Why  is  chloroform  used  in  pills  of  phosphorus? 
Chloroform  is  a  good  solvent  of  phosphorus,  and 
the  phosphorus  is  thereby  more  evenly  distributed 
through  the  pill  mass.  The  vapor  tends  to  prevent 
oxidation. 

POWDERS. 

Why  are  not  all  solids  suitable  for  administra- 
tion in  the  form  of  powders?  Because  some  are 
hygroscopic,  some  are  efflorescent,  some  are  changed 
by  the  air,  and  some  would  have  to  be  given  in 
too  large  doses.  Many  of  them  would  not  have 
the  effect  desired  if  given  in  a  concentrated  form. 
Many  of  the  very  soluble  salts  are  irritating  to  the 
alimentary  canal. 

Why  are  some  solids  best  given  in  the  form  of 
powders?  Because  in  such  form  they  may  act  as 
mechanical  protectives,  such  as  bismuth  subnitrate, 
for  instance.  Some  are  more  pleasant  and  con- 
venient to  take  in  this  way. 

Why  is  less  attention  to  incompatibilities  necessary 
in  dispensing  medicines  in  the  form  of  powders? 
Because  when  substances  are  kept  dry  and  not 
heated  there  is  but  little  danger  of  chemical  change. 

Why  is  it  better  to  dampen  such  substances  as 
resin,  acetanilid,  and  salol  with  alcohol  when  they 


PREPARATIONS.  55 

are  to  be  powdered?  Because  substances  of  this 
nature  become  more  or  less  electrified  by  the  rub- 
bing, and  adhere  to  the  utensils  or  are  scattered 
about,  and  alcohol  overcomes  this  tendencv. 

Why  are  compound  powders  directed  to  be  passed 
through  a  sieve?  This  breaks  up  all  the  lumps  and 
mixes  the  powders  more  thoroughly. 

Why  should  powders  for  insufflation  be  passed 
through  a  bolting-cloth?  This  overcomes  the  ten- 
dency to  making  a  dense  powder  by  trituration, 
leaving  it  light  and  fluffy. 

Why  is  syrup  better  than  water  as  a  vehicle  for 
the  administration  of  powders?  It  is  more  dense 
and  keeps  the  powder  suspended  better. 

Why  is  the  cachet  or  wafer  better  than  a  gelatin 
capsule  for  the  administration  of  powders?  Because 
the  cachet  when  wet  is  slippery  and  assumes  any 
form.  In  the  stomach  the  cachet  dissolves  more 
quickly  and  does  not  produce  the  sensation  of 
weight. 

Why  should  potassium  chlorate  not  be  triturated 
with  organic  matter?  Because  there  is  danger  of 
explosion. 

Why  should  camphor  be  dampened  with  alcohol 
before  being  powdered?  Because  it  can  then  be 
reduced  to  an  almost  impalpable  powder;  when 
rubbed  alone  it  cannot. 

Why  is  acacia  used  in  compound  chalk  powder? 
This  powder  is  used  only  in  making  chalk  mixture, 
and  the  acacia  helps  to  suspend  the  chalk. 


56  WHYS   IN   PHARMACY. 

Why  is  prepared  chalk  better  than  precipitated 
calcium  carbonate  in  making  compound  chalk 
powder?  It  is  not  crystalline  and  is  smoother,  less 
gritty. 

Why  is  the  mixture  of  sodium  bicarbonate  and 
Rochehe  salt  wrapped  separately  from  the  tartaric 
acid  in  Seidlitz  powders?  If  ah  the  ingredients  are 
mixed  together  moisture  from  the  air  is  absorbed 
and  chemical  reaction  takes  place.  Besides,  if  the 
mixture  of  the  three  ingredients  is  put  into  water 
effervescence  is  completed  before  all  of  the  Rochelle 
salt  is  dissolved. 

Why  are  two  different  colored  papers  used  in 
wrapping  Seidlitz  powders?  Because  if  only  one 
colored  paper  were  used  there  would  be  danger  of 
two  packages  of  the  salt  mixture  or  two  of  the 
acid  being  wrapped  together. 

Why  are  the  small  wooden  measures  used  for 
measuring  Seidlitz  powders  objectionable?  Because 
the  amount  the  measure  holds  varies  with  the  atmos- 
phere and  with  pressure,  and  the  measure  gets  worn 
so  that  it  holds  less  than  it  should. 

Why,  in  making  compound  licorice  powder,  is 
the  oil  of  fennel  mixed  with  the  sugar  rather  than 
with  the  senna?  Because  it  can  be  more  thoroughly 
and  readily  distributed  through  the  powder. 

Why  is  the  oil  of  fennel  preferred  to  the  powdered 
fennel  in  compound  licorice  powder?  Because  the 
preparation  keeps  better. 

Why  is  sugar  of  milk  in  as  coarse  powder  as  No.  30 


PREPARATIONS.  57 

used  in  making  Dover's  powder?  Because  in  that 
condition  it  is  gritty,  and,  in  powdering  it,  it  cuts  up 
and  divides  the  ipecac  and  opium  more  completely. 
Why  is  it  better,  in  making  compound  rhubarb 
powder,  to  mix  the  rhubarb  and  ginger  first,  and 
then  incorporate  the  magnesia?  The  magnesia  can 
be  more  readily  and  thoroughly  mixed  than  by 
mixing  the  powders  promiscuously. 

GRANULAR   EFFERVESCING  POWDERS. 

Why  are  effervescing  powders  frequently  preferred 
to  non-effervescing  powders?  Because  the  presence 
of  carbon  dioxide  makes  the  mixture  more  palatable. 

AVhy  is  the  method  of  granulating  by  heat  prefer- 
able to  that  of  dampening  with  alcohol?  Because 
there  is  less  danger  of  chemical  reaction  during  the 
process  of  manufacture,  and  because,  too,  it  requires 
a  much  shorter  time  for  drying. 

Why  is  citric  acid  used  instead  of  tartaric  acid  in 
granulating  with  heat?  Because  citric  acid  contains 
one  molecule  of  water  of  crystallization,  which  is 
liberated  by  heat  and  makes  a  mass  of  the  in- 
gredients. 

Why,  in  granulating  by  heat  and  passing  through 
a  sieve,  must  the  manipulations  be  carried  on  quickly? 
Because  the  water  of  crystallization  is  soon  driven 
off  and  the  mixture  loses  the  form  of  a  soft  mass. 

Why  should  the  mixture  of  sodium  bicarbonate 
and  acid  not  be  triturated  in  a  mortar?    Because 


58  WHYS   IN  PHARMACY. 

hard  pressure  induces  chemical  reaction  and  the 
consequent  liberation  of  carbon  dioxide. 

Why  is  it  better  to  mix  sugar  and  sodium  bicar- 
bonate together  before  mixing  with  the  acid?  The 
tendency  to  reaction  is  lessened. 

Why  must  strong  alcohol  be  used  in  granulating 
with  alcohol?  Because  the  water  that  the  alcohol 
contains  is  left  after  the  alcohol  is  evaporated,  and 
the  acid  and  sodium  bicarbonate  react  in  the  presence 
of  water. 

Why  must  salts  containing  a  large  amount  of 
water  of  crystallization  be  partially  dried  before 
granulating?  Because  frequently  the  water  is  liber- 
ated and  induces  the  chemical  reaction. 

Why  must  well-tinned  sieves  be  used  in  granulat- 
ing powders?  Because  the  acid  would  attack  the 
iron  or  copper  and  the  product  would  be  dis- 
colored. 

Why  must  granular  effervescing  powders  be  kept 
in  well-closed  containers?  Because  they  are  hygro- 
scopic, and,  absorbing  moisture,  chemical  reaction 
takes  place. 

Why  is  a  temperature  of  not  over  54°  C.  best  for 
drying  effervescing  powders?  Powders  thus  dried 
keep  better. 

Why  does  the  U.  S.  P.  give  the  title  Caffeina 
Citrata  Effervescens  instead  of  Caffeinse  Citras 
Effervescens?  Because  citric  acid  and  caffeine  are 
probably  not  combined,  simply  mixed. 

Why  is  citric  acid  used  in  slight  excess  in  the 


PREPARATIONS.  59 

formula  for  effervescing  lithium  citrate?    It  gives  a 
more  pleasant  taste  to  the  product. 

Why  does  the  U.  S.  P.  (1890)  direct  the  drying 
of  effervescing  magnesium  citrate  at  a  temperature 
not  above  30°  C?  Because  a  heat  above  that 
causes  the  formation  of  the  less  soluble  normal 
magnesium  citrate. 

RESINS. 

Why  is  hydrochloric  acid  used  in  making  resin 
of  mandrake?  It  renders  the  resin  less  soluble  in 
water. 

Why  does  the  resin  of  mandrake  of  commerce 
differ  in  color?  Because  other  substances  than 
hydrochloric  acid  are  used  in  precipitating  it,  and 
these  influence  the  color. 

SPIRITS. 

Why,  in  making  the  spirit  of  nitrous  ether,  is  the 
ethyl  nitrite  washed  with  water?  To  remove  any 
alcohol  that  may  have  distilled  over. 

Why,  in  making  the  spirit  of  nitrous  ether,  are 
sodium  and  potassium  carbonates  used?  Sodium 
carbonate  is  used  to  neutralize  the  acid  and  aid  its 
removal  from  the  distillate,  and  the  potassium 
carbonate  is  used  to  remove  the  last  part  of  water. 

Why  should  the  spirit  of  nitrous  ether  be  kept 
in  the  dark?  Light  tends  to  decompose  the  ethyl 
nitrite,  forming  alcohol  and  nitrous  and  nitric  acids. 


60  WHYS    IN   PHARMACY. 

Why  is  sulphuric  acid  used  in  estimating  spirit 
of  nitrous  ether?  To  hberate  nitrous  and  hydriodic 
acids  so  that  the  latter  will  decompose  the  former. 

Why,  in  making  spirit  of  ammonia,  should  alcohol 
recently  distilled  and  kept  in  glass  vessels  be  used? 
Alcohol  is  generally  kept  in  barrels  for  a  time,  and 
it  absorbs  organic  matter  which  is  colored  by 
ammonia;  by  using  the  recently  distilled  article  this 
coloration  is  avoided. 

Why  is  the  ammonia  water  heated  to  a  tem- 
perature not  exceeding  60°  C.  in  making  spirit  of 
ammonia?  A  higher  temperature  would  drive  over 
more  water  and  thus  dilute  the  alcohol. 

Why  is  ammonia  water  used  in  making  aromatic 
spirit  of  ammonia?  It  is  used  for  its  therapeutic 
effect  and  also  to  convert  the  ammonium  bicar- 
bonate into  the  normal  carbonate,  so  that  it  will 
be  soluble  in  alcohol. 

Why  does  the  U.  S.  P.  direct  ammonium  carbonate 
in  '' translucent  pieces"?  So  as  to  get  the  requisite 
amount  of  salt.  Opaque  pieces  have  lost  ammonia 
and  carbon  dioxide  and  consist  of  ammonium 
bicarbonate. 

Why  is  aromatic  spirit  of  ammonia  set  aside  for 
twelve  hours  before  being  filtered?  In  order  to  give 
time  for  the  ammonium  liydroxide  to  act  on  the  bi- 
carbonate. 

Why  does  aromatic  spirit  of  ammonia  turn  dark 
on  keeping  for  some  time?  Alcohol  frequently  con- 
tains   some    aldehyde    and    other   impurities    which 


PREPARATIONS.  61 

are  darkened  by  ammonia;  then  the  gradual  increase 
in  color  is  due  to  the  action  of  ammonia  on  the  oils. 

Why  should  whisky  be  at  least  four  years  old? 
So  as  to  allow  chemical  changes  to  take  place  whereby 
some  of  the  objectionable  impurities  are  changed, 
and  the  acids  combined  with  alcohols,  forming 
ethers  and  esters. 

Why  should  spirit  of  nitroglycerin  be  kept  in 
cans  rather  than  in  bottles?  Bottles  are  likely  to 
get  broken  and  the  spirit  leak  out.  The  alcohol, 
being  much  more  volatile  than  nitroglycerin,  the 
latter  is  left,  and  in  concentrated  condition  may  be 
exploded.  In  case  of  such  an  accident,  the  U.  S.  P. 
directs  the  use  of  potassium  hydroxide  to  decompose 
the  nitroglycerin. 

Why  is  peppermint  herb  used  in  making  spirit 
of  peppermint?    Chiefly  to  give  color. 

Why  should  spirits  of  peppermint  and  lemon  be 
protected  from  light?     Light  destroys  the  color. 

Why  is  it  better  to  wash  the  peppermint  herb  in 
water  before  using  in  making  spirit  of  peppermint? 
Water  takes  out  a  yellow  coloring  matter  so  that 
the  spirit  has  a  better  appearance. 

Why  add  the  water  '^ gradually"  in  making  bay 
rum  (1890)?  So  that  the  formation  of  a  permanent 
milkiness  may  be  avoided  as  far  as  possible. 

Why  is  bay  rum  (1890)  allowed  to  stand  eight 
days  before  filtering?  To  allow  the  mixture  of 
alcohol  and  water  to  dissolve  as  much  of  the  oils 
as  it  will,  and  also  to  let  the  excess  of  oils  separate 


62  WHYS   IN   PHARMACY. 

and  form  larger  globules,  making  them  more  easy 
to  filter  out. 

Why  is  absolute  alcohol  used  in  making  spirit  of 
phosphorus  (1890)?  It  is  a  better  solvent  than 
ordinary  alcohol,  which  dissolves  phosphorus  but 
shghtly. 

SUPPOSITORIES. 

Why  is  cacao  butter  a  good  suppository  base? 
Because  it  is  solid  at  ordinary  temperatures,  liquid 
at  the  temperature  of  the  body,  and  is  a  bland,  sooth- 
ing substance. 

Why,  in  hardening  cacao  butter  suppositories, 
must  care  be  used  not  to  get  too  much  of  the  harden- 
ing agent?  Since  the  base  does  not  dissolve  in  the 
alimentary  canal,  but  melts,  the  melting-point  must 
not  be  above  the  temperature  of  the  body. 

W^hy  are  hand-made  suppositories  preferable  to 
suppository  shells?  In  the  hand-made  suppositories 
the  medicinal  matter  is  mixed  throughout  the  sup- 
pository, while  in  the  shells  the  medicinal  matter  is 
not  absorbed  until  the  shell  has  been  entirely  melted, 
and  may  be  in  such  concentrated  form  as  to  be 
irritating. 

Why  must  a  suppository  mass  not  be  too  hot  when 
it  is  poured  into  molds?  If  it  contains  medicinal 
matter  insoluble  in  the  melted  base,  the  insoluble 
matter  will  sink  to  the  apex  of  the  cone. 

Wliy  is  a  base  of  gelatin  and  glycerin  sometimes 


PREPARATIONS.  63 

preferred  to  cacao  butter  in  making  urethral  and 
nasal  suppositories?    Because  it  is  less  likely  to  break. 

Why  should  gelatin  not  be  used  as  a  base  for 
ichthyol  suppositories?  Ichthyol  makes  gelatin  in- 
soluble. 

Why  are  glycerin  suppositories  preserved  in  tight 
vessels?  Because  they  are  sufficiently  hygroscopic 
to  become  liquid  when  exposed  to  the  air. 

Why  are  suppositories  containing  tannic  acid  best 
made  in  the  cold?  Because  a  heat  not  much  above 
the  temperature  necessary  for  melting  the  base  will 
cause  the  acid  to  form  tough,  hard  masses. 

Why  should  iodoform  suppositories  not  be  made 
with  heat?  The  overheating  of  iodoform  in  cacao 
butter  causes  it  to  form  masses. 

SYRUPS. 

Why  should  an  excess  of  sugar  be  avoided  in  mak- 
ing syrups  by  heat?  In  cooling,  the  excess  crystal- 
lizes out  and  more  besides,  leaving  a  solution  that 
has  been  weakened  sufficiently  to  be  apt  to  fer- 
ment. 

Why  do  some  persons  claim  that  heat  is  objection- 
able in  making  simple  syrup?  Continued  heat 
inverts  sugar  to  some  extent,  making  it  more 
likely  to  ferment. 

Why  does  a  syrup  that  has  once  fermented  quickly 
ferment  again,  even  after  it  is  boiled?  (1)  The 
spores  of  the  micro-organisms  may  not  all  have  been 


64  WHYS   IN   PHARMACY. 

killed;  (2)  the  proportion  of  sugar  has  been  dimin- 
ished by  fermentation;  and  (3)  part  of  the  sugar 
has  been  inverted,  in  which  condition  it  more  readily 
ferments. 

Why  does  syrup  of  acacia  undergo  decomposition 
more  quickly  than  simple  syrup?  Because  acacia 
in  water  spoils  quickly.  The  preparation  keeps 
better  than  when  made  by  the  previous  formula. 

Why  does  syrup  of  lemon  spoil  more  quickly 
than  syrup  of  citric  acid?  Syrup  of  lemon,  being 
made  from  lemon  juice,  contains  some  albumin 
which  always  tends  to  cause  decomposition. 

Why  does  syrup  of  citric  acid  sometimes  acquire 
a  turpentine  odor  and  taste?  Oil  of  lemon  changes 
on  exposure. 

Why  is  syrup  of  citric  acid  slightly  opalescent? 
Tincture  of  lemon  is  used  in  making  it,  and  the  oil, 
separated  from  the  alcohol  by  the  syrup,  causes 
the  turbidity. 

AVhy  is  althsea  washed  with  cold  water  in  making 
syrup  of  althsea  (1890)?  To  remove  dust  and  im- 
purities. 

Why  is  althsea  macerated  with  cold  water  instead 
of  hot?  Hot  water  makes  a  preparation  that  is  thick 
and  stringy. 

Why  are  alcohol  and  glycerin  used  in  syrup  of 
altha?a?    They  act  as  preservatives. 

Why  is  magnesium  carbonate  used  in  making 
syrup  of  orange?  To  aid  the  removal  of  finely  pre- 
cipitated matter. 


PREPARATIONS.  65 

Why,  in  making  syrup  of  calcium  lactophosphate, 
does  the  U.  S.  P.  start  with  calcium  carbonate  in- 
stead of  calcium  phosphate,  since  calcium  phosphate 
is  ultimately  formed?  While  calcium  phosphate  is 
soluble  in  acids,  it  is  much  less  readily  soluble  after 
it  has  been  dried.  In  following  the  official  direc- 
tions the  calcium  phosphate  may  be  dissolved  in  the 
nascent  condition.  The  phosphoric  acid  is  diluted 
to  prevent  precipitation. 

Why  is  syrup  of  lime  boiled  in  a  copper  or  tinned- 
iron  vessel  instead  of  glass  or  porcelain?  The  hot 
alkahne  solution  would  be  hable  to  attack  the  glass 
or  porcelain. 

Why  must  syrup  of  lime  be  well  protected  from 
the  air?  It  absorbs  carbon  dioxide  from  the  air, 
forming  calcium  carbonate,  which  is  precipitated. 

Why  is  syrup  of  lime  stronger  than  lime  water? 
Lime  combines  with  sugar  to  form  various  saccharates 
which  are  more  soluble  than  calcium  hydroxide,  and 
which,  being  loose  combinations,  are  easily  decom- 
posed, thus  acting  as  calcium  hydroxide  does. 

Why  is  an  excess  of  iron  over  iodine  used  in  mak- 
ing the  syrup  of  iodide  of  iron?  Because  if  an  ex- 
cess of  iodine  were  used  it  could  not  be  removed  by 
filtration  as  iron  can  be.  The  excess  of  iron  also 
aids  reaction  and  prevents  oxidation. 

Why  is  the  reaction  more  rapid  after  some  ferrous 
iodide  has  been  formed  in  making  syrup  of  iodide 
of  iron?  Chemical  reaction  generates  heat  and  heat 
aids   reaction.      Also    the    ferrous    iodide   dissolves 


66  WHYS   IN   PHARMACY. 

iodine  and  gets  it  into  form  so  that  it  will  react 
more  readily  with  iron. 

Why  is  it  necessary  to  check  the  reaction  between 
iron  and  iodine?  Sometimes  the  heat  generated  is 
sufficient  to  crack  the  vessel  or  to  volatilize  the 
iodine. 

Why,  in  making  the  syrup  of  iodide  of  iron,  is 
the  mixture  of  iodine,  iron,  and  water  heated  to 
boiling  before  filtering?  So  as  to  complete  the  chemi- 
cal reaction. 

Why  is  sugar  added  to  the  solution  of  ferrous 
iodide  before  filtering?  Sugar  has  a  reducing  action 
and  tends  to  prevent  the  oxidation  of  ferrous  iodide. 

Why  is  hypophosphorous  acid  added  to  the  syrup 
iodide  of  iron?  To  prevent  oxidation  and  liberation 
of  iodine. 

Why  does  syrup  iodide  of  iron  become  red?  Iodine 
is  gradually  liberated  and  dissolved.  Sometimes  cara- 
melization  of  the  sugar  takes  place. 

Why  should  syrup  of  ferrous  iodide  be  kept  in 
direct  sunhght?  Direct  sunlight  prevents  or  retards 
the  liberation  of  iodine  and  reduces  it  after  it  has 
been  liberated. 

Why  should  bottles  containing  syrup  of  iodide  of 
iron  be  kept  full?  To  avoid  contact  with  air  which 
oxidizes  it. 

Why  should  the  syrup  of  the  phosphate  of  iron, 
quinine,  and  strychnine  be  protected  from  hght? 
Light  gradually  causes  a  chemical  change  in  the  iron, 
resulting  in  a  darkened  preparation. 


PREPARATIONS.  67 

Why  is  hypophosphorous  acid  used  in  syrup  of 
hypophosphites?  It  aids  the  solution  of  the  hypo- 
phosphites,  particularly  the  calcium  salt.  It  also 
gives  a  more  pleasant  taste. 

Why  is  potassium  citrate  used  in  compound  syrup 
of  hypophosphites?  To  aid  the  solution  of  iron  and 
manganese  hypophosphites. 

Why  is  potassium  citrate  used  in  the  syrup  of 
hypophospliites  with  iron  (1890)?  An  alkali  citrate 
makes  the  ferrous  lactate  more  soluble,  and  it 
also  prevents  the  precipitation  of  hypophosphite 
of  iron. 

Why  should  syrup  of  hypophosphites  with  iron 
(1890)  be  freshly  made  when  wanted?  It  gradually 
changes,  becoming  darker. 

Why  must  calcium  phosphate  not  be  used  to  aid 
filtration  in  making  syrup  of  ipecac?  Because  it 
would  be  dissolved  by  the  acetic  acid. 

Why  is  acetic  acid  used  in  syrup  of  ipecac?  To 
convert  the  emetine  into  an  acetate  which  is  soluble. 

Why  is  glycerin  used  in  syrup  of  ipecac?  To  pre- 
vent souring;  the  syrup  soon  spoils  if  not  protected 
by  glycerin. 

W^hy  is  sand  used  in  making  syrup  of  tar?  To 
divide  the  tar  so  that  water  can  be  mixed  with  it 
better. 

Why  is  the  first  water  which  is  used  in  washing  tar 
thrown  away  in  making  syrup  of  tar?  Tar  generally 
contains  some  pyroligneous  acid  and  other  impuri- 
ties that  are  not  wanted. 


68  WHYS  IN   PHARMACY. 

Why  is  alcohol  used  in  syrup  of  tar?  For  its 
solvent  effect. 

Why  is  a  wild  cherry  bark  macerated  for  twenty- 
four  hours  in  making  syrup  of  wild  cherry?  To  allow 
the  ferment,  emulsin,  to  act  on  the  amygdalin,  form- 
ing hydrocyanic  acid  and  benzaldehyde. 

Why  must  the  sugar  be  dissolved  without  heat  in 
making  syrup  of  wild  cherry?  Heat  would  drive  off 
the  hydrocyanic  acid  and  benzaldehyde. 

Why  is  potassium  carbonate  used  in  syrup  of 
rhubarb  and  aromatic  syrup  of  rhubarb?  It  pre- 
vents the  precipitation  of  resinous  matter  by  form- 
ing a  soluble  compound  with  it. 

Why,  in  making  syrup  of  raspberries  (1890),  are 
the  raspberries  allowed  to  stand  until  the  filtered 
juice  mixes  clear  with  half  its  volume  of  alcohol? 
Raspberries  contain  a  pectinous  substance  which,  if 
left  in,  tends  to  cause  the  decomposition  of  the 
syrup.  It  is  destroyed  or  precipitated  by  this  fer- 
mentation and  a  clear  solution  of  the  filtrate  with 
alcohol  indicates  that  it  has  been  removed. 

Why  is  syrup  of  raspberries  (1890)  heated  to  boil- 
ing? To  precipitate  any  albuminous  matter  which 
may  be  left  in  and  to  destroy  ferments. 

Why  is  the  mixture  of  the  ingredients  of  com- 
pound syrup  of  sarsaparilla  set  aside  for  an  hour 
before  filtering?  To  allow  nearly  complete  precipi- 
tation. 

Why  is  the  vinegar  of  squills  heated  to  boiling  in 
making  syrup  of  squills  (1890)?    The  vinegar  con- 


PREPARATIONS.  69 

tains  albuminous  matter  which  is  coagulated  by  heat 
and  can  then  be  filtered  out.  Albuminous  matter 
tends  to  cause  fermentation. 

Why  in  making  syrup  of  squills  is  the  vinegar  not 
boiled  and  strained?  It  is  not  now  necessary  since 
in  making  the  vinegar  the  liquid  is  boiled  and  the 
albumin  removed. 

Why  must  a  metallic  vessel  not  be  used  in  making 
syrup  of  squills?  The  acetic  acid  would  attack  the 
vessel. 

Why  is  talc  used  in  making  compound  syrup  of 
squills?  To  aid  the  removal  of  the  finely  precipitated 
inert  matter. 

Why  is  potassium  carbonate  used  in  compound 
syrup  of  asarum,  N.  F.?  To  make  soluble  com- 
pounds with  the  resin  in  the  asarum  and  the  coloring- 
matter  of  the  cochineal. 

Why  is  citric  acid  used  in  syrup  of  calcium  and 
sodium  hypophosphites,  N.  F.?  To  aid  solution  and 
to  give  the  preparation  an  acid  taste. 

Why  is  iodine  added  to  the  solution  of  ferrous 
iodide  in  making  syrup  of  iodide  of  calcium,  N.  F.? 
To  form  the  ferric  iodide. 

Why  is  the  iron  wanted  in  the  ferric  condition  in 
making  syrup  of  calcium  iodide,  N.  F.?  So  that  the 
reaction  with  calcium  carbonate  will  be  more  com- 
plete, there  being  formed  ferric  hydroxide,  which  is 
precipitated,  and  calcium  iodide,  which  is  left  in 
solution. 

Why  is  potassium  citrate  used  in  syrup  of  calcium 


70  WHYS   IN    PHARMACY. 

lactophosphate  with  iron,  N.  F.?  To  aid  the  solution 
of  iron  lactate. 

Why  is  solution  of  potassium  hydroxide  used  in 
aromatic  syrup  of  yerba  santa?  To  prevent  the  pre- 
cipitation of  resinous  matter  by  forming  a  soluble 
compound. 

Why  is  iodine  added  to  ferrous  iodide  in  making 
syrup  of  citro-iodide  of  iron,  N.  F.?  To  convert  the 
ferrous  iodide  into  the  ferric  iodide,  that  salt  being 
wanted. 

Why  is  potassium  citrate  used  in  making  syrup  of 
hypophosphite  of  iron,  N.  F.?  Hypophosphite  of 
iron  is  only  sparingly  soluble  in  water,  but  readily 
soluble  in  an  aqueous  solution  of  a  citrate  probably 
forming  a  double  compound. 

Why  is  acetic  acid  used  in  syrup  of  sanguinaria, 
N.  F.?    To  prevent  precipitation. 

TINCTURES. 

Why  is  glycerin  used  in  making  tinctures?  To  aid 
in  dissolving  the  active  matter,  particularly  when 
this  is  tannic  acid,  and  to  retard  or  prevent  subse- 
quent changes  and  precipitation. 

Why  is  the  period  of  maceration  shorter  in  making 
tinctures  than  in  making  fluid  extracts?  Because  the 
proportion  of  the  menstruum  to  the  drug  is  much 
greater. 

Why  are  some  drugs  put  into  the  percolator  with- 
out previous  dampening   in  making  tinctures?     Be- 


PREPARATIONS.  71 

cause  if  they  are  first  dampened  they  would  pack  too 
tight  in  the  percolator  and  the  menstruum  could  not 
pass  through. 

Why  is  evaporation  not  necessary  in  making  tinc- 
tures as  it  is  in  making  fluid  extracts?  Because  by 
the  time  enough  menstruum  is  used  to  get  the  re- 
quired percolate  the  drug  is  exhausted. 

Why  should  tinctures  not  be  made  from  fluid  ex- 
tracts? Because  the  menstruums  used  in  making 
the  two  classes  of  preparations  are  not  always  identi- 
cal, and  not  infrequently  the  activity  of  the  drug 
is  modified  by  the  heat  necessary  in  making  fluid 
extracts. 

Why  do  tinctures  of  a  fresh  herb  vary  both  in 
alcoholic  strength  and  therapeutic  value?  Because 
the  amount  of  water  present  at  different  times 
varies. 

Why  is  the  process  of  maceration  sometimes  pref- 
erable to  percolation?  Some  drugs  are  resinous  and 
of  such  nature  that  they  cannot  be  percolated. 

Why  is  tincture  of  arnica  made  by  maceration  and 
expression?  The  flowers  are  bulky  and  less  alcohol 
is  required  than  if  they  were  percolated. 

Why  are  tinctures  of  sweet  orange-peel  and  lemon- 
peel  made  by  maceration  ?  The  fresh  peels  are  used 
and  it  is  difficult  to  get  the  peels  in  suitable  form  for 
percolation. 

Why  is  the  sweet  orange-peel  deprived  of  its 
inner  white  part  in  making  the  tincture?  The  white 
part  contains   tannin  and   hesperidin,  which  make 


72  WHYS   IN    PHARMACY. 

the  preparation  objectionable  when  dispensed  with 
iron. 

Why  is  cinnamon  used  in  compound  tincture  of 
gambir?  To  aid  filtration  and  give  a  more  pleasant 
taste. 

Why  is  the  tincture  of  ferric  chloride  set  aside  for 
three  months?  So  as  to  allow  chemical  reaction  to 
take  place  between  the  free  acid  and  the  alcohol, 
which  results  in  the  formation  of  chloric  ether  and 
other  compounds  which  are  supposed  to  have  a 
diuretic  effect.  One  writer  claims  that  the  ether 
is  the  result  of  action  between  ferric  chloride  and 
alcohol,  ferric  hydroxide  being  precipitated;  he  also 
claims  that  aldehyde,  ferrous  chloride  and  free  hydro- 
chloric acid  are  formed  by  action  of  ferric  chloride 
on  alcohol. 

Why  should  tincture  of  iron  be  protected  from  the 
light?     Light  reduces  it  to  the  ferrous  condition. 

Why  does  a  tincture  of  iron  that  is  perfectly  clear 
when  first  made  sometimes  precipitate  on  standing? 
A  certain  amount  of  free  acid  is  necessary  to  prevent 
the  precipitation  of  an  oxychloride  of  iron,  and,  as 
the  acid  becomes  used  up  in  the  chemical  reaction 
which  slowly  takes  place,  the  oxysalt  is  precipi- 
tated. 

Why  does  the  addition  of  glycerin  to  tincture  of 
ferric  chloride  increase  the  color?  Glycerin,  as  well 
as  water,  alcohol  and  other  liquids,  darkens  the  tinc- 
ture on  account  of  partial  hydrolysis  of  ferric  chlo- 
ride into  the  hydroxide  and  hydrochloric  acid.     The 


PREPARATIONS.  73 

ferric  hydroxide  remains  dissolved  in  the  acid  solu- 
tion. 

Why  is  it  advisable  to  use  a  high  grade  of  alcohol 
in  making  tincture  of  iodine?  If  the  alcohol  con- 
tains aldehyde  or  the  higher  homologues  the  iodine 
is  changed  more  qucikly  to  hydriodic  acid. 

Why  is  it  that  a  freshly-made  tincture  of  iodine 
(1890)  gives  a  precipitate  of  iodine  when  an  old  one 
may  not?  An  old  tincture  frequently  contains  some 
hydriodic  acid  which  is  gradually  formed,  and  this 
keeps  the  iodine  in  solution  even  in  the  presence  of 
water.  Precipitation  is  prevented  in  the  present 
formula  by  potassium  iodide.  Potassium  iodide  also 
aids  solution. 

Why  in  making  tincture  of  ipecac  and  opium  is 
the  tincture  of  deodorized  opium  evaporated  to  800 
grams  instead  of  900  cc,  which  with  the  100  cc.  of 
fluid  extract  would  make  the  1000  cc.  of  finished 
tincture?  In  evaporating  a  liquid  it  is  rather  more 
convenient  to  evaporate  to  a  given  weight  than  to  a 
given  volume  and  then  by  evaporating  below  900 
cc.  the  precipitate  can  be  filtered  out  and  the  filter 
washed  without  getting  too  much  filtrate. 

Why  is  talc  used  in  making  tincture  of  kino?  To 
aid  filtration. 

Why  should  tincture  of  kino  be  kept  in  small,  well- 
stoppered  bottles?  If  not  so  kept  it  is  likely  to 
gelatinize.  Glycerin  tends  to  prevent  gelatinization. 
The  amount  of  kino  is  now  reduced  one  half  and 
there  is  less  danger  of  gelatinization. 


74  WHYS    IN    PHARMACY. 

Why  is  sand  used  in  making  tincture  of  lactuca- 
rium?    To  cut  up  the  lactucarium  and  aid  percolation. 

Why  is  benzin  used  in  tincture  of  lacucarium?  To 
remove  lactucerin,  which  is  an  inert  caoutchouc-hke 
substance. 

Why  is  musk  first  rubbed  with  water  in  making 
tincture  of  musk?  Water  dissolves  out  more  of  the 
extractive  matter  than  alcohol. 

Why  is  tincture  of  nux  vomica  made  from  the 
extract?  It  gives  a  more  uniform  product,  and  is 
more  convenient. 

Why,  in  making  laudanum,  is  opium  macerated 
twelve  hours  with  water  before  adding  the  alcohol? 
Water  is  a  good  solvent  for  the  active  principles  and 
it  disintegrates  opium  better  than  alcohol. 

Why  is  benzin  used  in  making  tincture  of  deodor- 
ized opium?  To  remove  the  odorous  principle  and  the 
narcotine. 

Why  must  the  aqueous  opium  extract  and  benzin 
not  be  shaken  hard  in  making  deodorized  tincture 
of  opium?  If  shaken  vigorously  an  emulsion  will 
be  produced  which  requires  a  long  time  for  separa- 
tion. 

Why  is  boiling  water  used  in  making  tincture  of 
quillaja?  It  dissolves  out  the  saponin  more  readily 
than  an  alcoholic  menstruum  and  heat  does  not  de- 
compose it. 

Why  is  potassium  carbonate  used  in  aqueous  tinc- 
ture of  rhubarb  (1890)?  It  is  alkaline  and  prevents 
the  precipitation  of  resinous  matter. 


PREPARATIONS.  ,  75 

Why  is  acetic  acid  used  in  tincture  of  sanguinaria? 
It  aids  the  sokition  of  the  sanguinarine  and  retards 
or  prevents  precipitation. 

Why  should  the  oil  be  removed  from  the  tincture 
of  strophanthus?  The  preparation  is  brighter  in 
appearance  and  is  not  so  liable  to  cause  vomiting 
and  diarrhoea  when  the  oil  has  been  removed. 

Why  is  vanilla  macerated  with  the  menstruum 
previous  to  pounding  it  with  sugar  in  making  tinc- 
ture of  vanilla?  The  maceration  softens  it  so  that 
it  can  be  more  readily  disintegrated  by  the  sugar. 

Why  should  the  use  of  Fleming's  tincture  of 
aconite  be  discouraged?  The  tincture  representing 
seventy  per  cent,  of  drug,  the  drug  is  not  exhausted 
in  making  the  tincture;  besides,  this  tincture  is 
much  stronger  than  other  tinctures,  and  its  exist- 
ence is  not  necessary  in  view  of  the  existence  of 
the  official  fluid  extract  and  tincture. 

AVhy  is  ammonia  used  in  making  detannated  tinc- 
ture of  cinchona?  To  form  ferric  hydroxide  with 
solution  of  ferric  sulphate. 

Why  is  ferric  hydroxide  better  than  solution  of 
ferric  sulphate  for  removing  tannin?  Ferric  hydrox- 
ide combines  with  tannin  to  form  an  insoluble  com- 
pound, which,  with  the  excess  of  ferric  hydroxide, 
can  be  removed  by  filtration.  Ferric  sulphate  forms 
a  soluble  compound  with  tannin,  which,  with  the 
excess  of  iron  salt,  cannot  be  removed  by  filtra- 
tion. 

Why,  in  making  ethereal  tincture  of  iron,  is  the 


76  WHYS   IN    PHARMACY. 

mixture  of  alcohol,  ether,  and  solution  of  ferric 
chloride  placed  in  direct  sunlight?  Light  reduces 
the  iron  to  the  ferrous  condition,  and  at  the  same 
time  other  changes  take  place  resulting  in  the  forma- 
tion of  chloric  ether. 

Why  is  ethereal  tincture  of  iron  put  into  a  shady 
place  after  being  decolorized?  Partial  oxidation 
results  and  the  mixture  contains  ferrous  and  ferric 
iron. 

Why  does  a  deposit  form  in  the  tincture  of  citro- 
chloride  of  iron?  Because  the  alcohol  throws  the 
sodium  chloride  out  of  solution. 

Why  is  potassium  carbonate  used  in  making  com- 
pound tincture  of  guaiac?  To  prevent  precipitation 
of  resinous  matter,  the  alkali  forming  a  somewhat 
soluble  compound  with  it. 

Why  is  potassium  iodide  used  in  Churchiirs  tinc- 
ture of  iodine?  To  help  keep  the  iodine  in  solution, 
as  water  precipitates  it  from  alcoholic  solution. 

Why  are  sodium  thiosulphate  and  ammonia  water 
used  in  decolorized  tincture  of  iodine?  They  de- 
colorize iodine  by  reducing  it  chiefly  to  the  iodide 
of  sodium  and  iodide  of  ammonium.  There  is  also 
a  little  iodate  formed. 

Why  put  decolorized  tincture  of  iodine  into  a  cool 
place  before  filtering?  To  aid  the  precipitation  of 
sodium  tetrathionate. 

Why  should  the  use  of  decolorized  tincture  of 
iodine  be  discouraged?  The  title  of  the  tincture  is 
misleading,  as  in  reality  the  preparation  is  a  tincture 


PREPARATIONS.  i  i 

of  the  iodides  of  sodium  and  ammonium  and  does 
not  have  the  physiological  effect  of  iodine. 

TROCHES, 

Why  is  tragacanth  preferable  to  acacia  in  making 
lozenges?     It  makes  a  more  tenacious  mass. 

Why  is  a  gelatin  base  objectionable  in  making 
lozenges  containing  tannic  acid?  The  tannic  acid  com- 
bines with  gelatin  to  form  an  insoluble  compound. 

AVhy  are  fine  powders  not  suited  for  making  com- 
pressed tablets?  Air  gets  in  between  the  particles 
and  is  held  there  so  that  the  particles  do  not  stick 
together.     A  granulated  powder  works  much  better. 

Why  should  tablet  triturate  molds  not  be  washed 
with  hot  water?  They  are  generally  made  of  rubber 
and  heat  warps  them. 

Why  is  starch  used  in  making  compressed  tablets? 
Starch  may  be  used  as  a  dilutent  and  it  also  has  the 
property  of  making  the  tablet  disintegrate  more 
quickly. 

OINTMENTS. 

Why  should  an  ointment  base  be  free  from  ran- 
cidity? Because  of  the  odor  and  because  the  free 
acid  is  frequently  irritating  and  may  sometimes 
cause  chemical  reaction. 

Why  is  yellow  wax  better  than  white  wax  for 
ointments?  In  bleaching  wax  it  undergoes  a  change 
which  makes  it  more  liable  to  become  rancid. 


78  WHYS   IN    PHARMACY. 

Why  is  hydrous  wool-fat  a  good  ointment  base 
in  certain  cases?  Because  it  is  readily  absorbed, 
carrying  with  it  the  medicinal  agent,  and  it  can  be 
mixed  with  a  large  percentage  of  water  without 
losing  its  ointment  properties.  Moreover,  it  fre- 
quently aids  in  making  an  ointment  when  liquids 
are  called  for  which  are  not  miscible  with  the  pre- 
scribed base. 

Why  does  the  U.  S.  P.  allow  as  much  as  30  per 
cent,  of  water  in  hydrous  wool-fat?  Anhydrous  wool- 
fat  is  very  tough  and  sticky,  and  the  presence  of  30 
per  cent,  of  water  gives  it  the  proper  consistency  for 
an  ointment  base. 

Why  is  wool-fat  recognized  in  addition  to  the 
hydrous  wool-fat?  The  anhydrous  fat  is  good  for 
ointments  containing  water,  and  also  good  in  cases 
where  water  is  objectionable. 

Why  is  lard  a  good  ointment  base?  It  is  cheap, 
fairly  readily  absorbed,  and  will  mix  with  some 
water. 

Why  is  petrolatum  a  good  ointment  base  in  cer- 
tain cases?  It  is  cheap,  is  not  readily  absorbed,  and 
consequently  acts  as  a  protective,  and  does  not  be- 
come rancid. 

Why  is  glycerite  of  starch  a  good  ointment  base  in 
certain  cases?  Because  it  is  not  greasy  and  can  be 
easily  washed  off. 

Why  should  medicinal  agents  be  mixed  with  a 
small  portion  of  the  base  first?  Because  they  can 
be  nmcli  more  readily  and  thoroughly  mixed. 


PREPARATIONS.  79 

Why  should  a  solid  be  in  an  impalpable  powder 
before  mixing  with  the  ointment  base?  Because  it  is 
almost  impossible  to  powder  after  mixing. 

Why  are  moderately  soluble  salts  better  rubbed 
with  a  little  oil  rather  than  with  water  in  making 
ointments?  If  dissolved  in  water  the  latter  will 
evaporate  and  the  salts  will  crystallize  and  possibly 
become  irritating. 

Why  should  ointments  be  stirred  when  cooling? 
Because  the  ingredients  having  the  higher  melting- 
points  will  sometimes  solidify  first,  making  a  gran- 
ular ointment. 

Why  is  paraffin  an  objectionable  substitute  for 
wax  in  ointments?  Because  it  is  liable  to  make  the 
ointment  granular. 

Why  should  agents  that  are  likely  to  react  with  one 
another  in  an  ointment  be  rubbed  separately  with 
some  of  the  greasy  base  and  then  mixed?  They  are 
protected  by  the  base  so  that  they  do  not  come  in 
sufficiently  intimate  contact  to  react. 

Why  should  the  temperature  not  rise  above  60°  C. 
in  making  benzoated  lard?  A  higher  temperature 
volatilizes  to  a  greater  or  less  extent  the  benzoic  acid 
and  volatile  oil. 

Why  should  an  iron  spatula  not  be  used  in  making 
tannic-acid  ointment?  Tannic  acid  attacks  iron 
forming  a  little  tannate  of  iron,  which  gives  a  dark- 
ened ointment.  If  the  spatula  is  first  smeared  with 
the  fatty  base  there  is  but  little  danger. 

Why  should  heat  not  be  used  in  making  ointment 


80  WHYS   IN   PHARMACY. 

of  tannic  acid?  If  the  mixture  is  heated  only  a 
little  above  the  melting-point  of  lard  the  acid  be- 
comes sticky  and  forms  tough  masses  that  cannot 
be  distributed  through  the  base.  The  glycerin  re- 
lieves this  trouble. 

Why  should  a  horn  spatula  be  used  in  making  an 
ointment  containing  salicylic  acid?  If  an  iron  one 
were  used  the  iron  might  be  attacked  slightly,  caus- 
ing a  pinkish  color  due  to  the  formation  of  salicylate 
of  iron. 

Why  is  rose  water  used  in  cold  cream  instead  of 
enough  oil  of  rose  to  perfume?  Water  makes  the 
ointment  more  soft  and  creamy. 

Why  is  it  better  to  stir  rose-water  ointment  for 
some  time?    The  longer  it  is  stirred  the  whiter  it  is. 

Why  is  borax  used  in  cold  cream?  To  give  a 
whiter  and  more  creamy  preparation. 

Why  is  borax  in  cold  cream  sometimes  objection- 
able? Because  it  is  alkaline  and  reacts  with  some 
of  the  agents  that  are  sometimes  used  with  the 
ointment. 

Why  must  the  melted  mixture  of  lead  plaster  and 
olive  oil  be  partly  cooled  before  adding  the  oil  of 
lavender  in  making  diachylon  ointment?  The  oil  of 
lavender  would  otherwise  be  volatilized. 

AVhy  is  oleate  of  mercury  used  in  making  mer- 
curial ointment?  Because  it  is  a  good  agent  for 
extinguishing  mercury. 

Why  should  mercurial  ointment  be  kept  in  a  cool 
place?     If  it  is  warmed  the  mercvuy  will  separate. 


PREPARATIONS.  81 

Why  is  the  term  '^blue  ointment"  now  apphed  to 
the  diluted  mercurial  ointment?  Many  customers 
buy  blue  ointment  to  be  used  without  the  physician's 
directions^  and  in  many  cases  the  fifty  per  cent, 
ointment  is  too  strong. 

Why  do  samples  of  citrine  ointment  vary  in  color 
and  consistency?  Because  of  the  variation  of  heat 
used,  and  also  on  account  of  lard  being  frequently 
adulterated.  This  does  not  always  explain  the  reason 
for  variation,  however,  as  samples  are  not  always  the 
same  even  when  made  with  the  same  ingredients  and 
at  the  same  temperature. 

Why  should  a  metallic  spatula  be  avoided  in 
handling  citrine  ointment?  The  ointment  is  acid 
and  attacks  iron. 

Why  does  citrine  ointment  sometimes  become  dark 
colored  when  it  is  mixed  with  an  alkali?  Because 
the  mercury  has  been  partly  reduced  to  the  mercurous 
condition  and  the  alkali  causes  the  black  oxide  to  be 
formed. 

Why  does  ointment  of  red  oxide  of  mercury  (1890) 
become  discolored?  The  base  becomes  rancid  and 
slowly  reduces  the  mercury. 

Why  is  lanolin  better  for  making  ointment  of  the 
oxides  of  mercury  than  simple  ointment?  The  mer- 
cury oxides  are  not  so  readily  reduced. 

Why  should  heat  not  be  used  in  making  ointment 
of  iodoform?  Heat  causes  iodoform  to  cake  into 
masses. 

Why   is    potassium   iodide   used   in   ointment   of 


82  WHYS    IN    PHARMACY. 

iodine?  Iodine  cannot  be  reduced  to  an  impalpable 
powder,  but  it  is  very  soluble  in  an  aqueous  solution 
of  potassium  iodide,  and  this  solution  can  be  inti- 
mately mixed  with  the  base. 

Why  is  water  used  in  ointment  of  potassium  iodide? 
Potassium  iodide  is  difficult  to  powder,  but  is  very 
soluble  in  water,  and  in  solution  can  be  more  thor- 
oughly mixed  with  the  base. 

Why  is  potassium  carbonate  used  in  making  oint- 
ment of  potassium  iodide?  Free-fat  acids  that  are 
in  lard  when  a  little  rancid  liberate  iodine,  coloring 
the  ointment.     Potassium  carbonate  prevents  this. 

Why  is  lanolin  better  than  lard  for  ointment  of 
zinc  oxide?  The  ointment  is  not  so  liable  to  become 
granular.     * 

WINES- 

Why  is  white  wine  used  in  preference  to  red  wine 
in  making  medicinal  wines?  It  contains  less  tannin 
and  consequently  has  fewer  incompatibilities. 

Why  is  wine  fortified  with  alcohol  in  making 
medicinal  wines?  To  make  the  preparations  more 
permanent. 

Why  is  ferric  hydroxide  objectionable  as  a  detan- 
nating  agent  for  wine?  Wine  contains  potassium 
acid  tartrate,  and  this  dissolves  a  little  iron. 


CHEMICALS. 


ACIDS. 


Why  is  dilute  acetic  acid  preferred  to  vinegar  in 
making  pharmaceutical  preparations?  It  is  stronger, 
more  uniform  in  strength,  free  from  color,  and  prepa- 
rations made  with  it  keep  better. 

Why  was  acetic  acid,  sp.  gr.  1.04  (twenty-nine 
per  cent.),  called  ''No.  8"?  It  was  formerly  used 
in  the  proportion  of  one  part  of  acid  to  eight  of  water 
in  making  dilute  acid. 

Why  should  bottles  containing  acetic  acid  not  be 
stoppered  with  rubber?  The  acid  is  likely  to  become 
contaminated  with  substances  used  in  the  vulcan- 
izing of  the  rubber. 

Why  is  litmus  not  a  good  indicator  in  estimating 
acetic  acid  in  a  liquid  by  means  of  a  standard  alkali 
solution?  Acetates  though  normal  in  composition 
are  alkaline  to  litmus,  thus  producing  a  lower  result 
than  is  correct.  Phenolphthalein  is  better  for  all 
organic  acids. 

Why  in  making  acetic  acid  is  distillation  of  wood 

carried  on  slowly  at  a  temperature  below  218°  C? 

83 


84  WHYS   IN    PHARMACY. 

The  yield  of  acid  is  larger,   the  distillate  contains 
less  empyreumatic  matter,  and  the  charcoal  is  better. 

Why  can  not  the  determination  of  the  specific 
gravity  of  acetic  acid  be  relied  on  as  a  means  of  de- 
termining its  strength?  The  specific  gravity  in- 
creases until  the  acid  is  about  seventy-seven  per 
cent,  strong;  then  it  remains  about  constant  until 
the  acid  is  about  eighty  per  cent,  when  the  specific 
gravity  begins  to  decrease.  Acetic  acid  of  ninety- 
nine  per  cent,  has  about  the  same  specific  gravity 
as  that  of  forty-six  per  cent. 

Why  does  the  odor  of  benzoic  acid  vary?  Because 
it  is  obtained  from  different  sources  and  retains  to 
some  extent  the  odor  of  the  substance  from  which 
obtained. 

Why  is  hydrochloric  acid  better  than  sulphuric 
acid  in  making  boric  acid  from  borax?  Sodium 
chloride  is  more  easily  washed  out  than  sodium 
sulphate,  and  it  is  said  that  under  certain  conditions 
sulphuric  acid  combines  with  boric  acid.  More  crys- 
tallizations are  necessary  to  purify  the  acid  when 
sulphuric  acid  is  used.  Sodium  nitrate  is  more 
readily  washed  out  than  the  sulphate  or  chloride. 

Why  is  the  juice  of  lemons  boiled  in  making  citric 
acid?  Heat  coagulates  albuminous  matter  so  that 
it  can  be  removed  by  filtration. 

Why  does  the  U.  S.  P.  allow  a  little  sulphuric  acid 
as  an  impurity  in  citric  acid?  Excess  of  sulphuric 
acid  is  added  to  the  calcium  citrate  to  prevent  the 
formation  of  calcium-acid  citrate  which  would  hinder 


CHEMIC.VLS.  85 

crystallization.  Citric  acid  crystallizes  better  in  the 
presence  of  a  little  sulphuric  acid. 

Why  is  lead  sometimes  an  impurity  in  citric  acid? 
The  acid  is  usually  crystallized  in  lead  vats  and  dis- 
solves a  little  metal. 

Why  is  potassium  hypophosphite  used  in  making 
dilute  hydriodic  acid?  Hydriodic  acid  is  oxidized 
by  air,  liberating  iodine,  and  potassium  hypophos- 
phite or  hypophosphorous  acid  reduces  it  again. 

Why  is  alcohol  used  in  making  dilute  hydriodic 
acid?  To  cause  the  more  complete  precipitation  of 
cream  of  tartar  formed  by  the  chemical  reaction. 

Why  is  the  mixture  of  ingredients  in  hydriodic 
acid  set  aside  in  ice  water  before  filtering?  To  pre- 
cipitate the  cream  of  tartar. 

Why  in  making  dilute  hydriodic  acid  is  the  filter 
washed  with  dilute  alcohol  instead  of  water?  Dilute 
alcohol  does  not  dissolve  cream  of  tartar  as  water 
does. 

Why  in  making  dilute  hydriodic  acid  should  the 
filter  be  washed  until  the  filtrate  does  not  give  a 
turbidity  with  silver-nitrate  solution?  Absence  of 
turbidity  shows  that  the  hydriodic  acid  has  been 
all  washed  into  the  filtrate  which  is  the  part 
used. 

Why  is  arsenic  frequently  an  impurity  in  hydro- 
chloric acid?  Sulphuric  acid,  which  is  used  in  mak- 
ing hydrochloric  acid,  is  often  contaminated,  arsenic 
occurring  in  the  iron  pyrites  from  which  sulphuric 
acid  is  made. 


86  WHYS    IN    PHARMACY. 

Why  is  commercial  hydrochloric  acid  colored  red? 
The  color  is  due  to  impurities,  such  as  iron  and 
organic  matter. 

Why  does  concentrated  hydrochloric  acid  give  rise 
to  white  fumes  when  exposed  to  air?  These  are  due 
largely  to  the  formation  of  ammonium  chloride  by 
combination  with  the  ammonia  of  the  air. 

Why  is  the  neck  of  the  retort  directed  upward  in 
making  dilute  hydrocyanic  acid  (1890)?  There  is 
some  liability  of  sulphuric  acid  being  carried  over 
and  this  arrangement  is  to  lessen  that  liability. 

Why  does  the  U.  S.  P.  give  the  method  of  making 
dilute  hydrocyanic  acid  from  silver  cyanide  instead 
of  from  potassium  ferrocyanide?  Hydrocyanic  acid 
does  not  keep  well  and  can  be  made  up  extempo- 
raneously from  silver  cyanide  without  having  to  assay 
it,  although  this  method  is  more  expensive. 

Why  should  the  use  of  Scheele's  hydrocyanic  acid 
be  discouraged?  It  is  two  and  one  half  times  as 
strong  as  the  official  acid,  does  not  keep  as  well,  and 
is  more  variable  and  less  reliable. 

Why  should  dilute  hydrocyanic  acid  be  kept  in 
small,  dark,  amber-colored,  cork-stoppered  bottles? 
Light  causes  the  formation  of  the  dark-colored  para- 
cyanogen.  Moreover,  Squibb  found  by  experiment 
that  the  acid  keeps  better  in  cork-stoppered  bottles, 
probably  because  a  cork  fits  tighter  than  a  glass 
stopper. 

Why  is  diluted  alcohol  used  in  making  dilute  hypo- 
phosphorous  acid,  N.  F.?    To  make  the  potassium 


CHEMICALS.  87 

bitartrate  more  insoluble  so  that  the  acid  will  be 
purer. 

Why  is  the  mixture  of  solution  of  potassium  hypo- 
phosphite  and  of  tartaric  acid  set  aside  in  a  cool 
place  for  twelve  hours  in  making  dilute  hypophos- 
phorous  acid?  Because  this  increases  the  precipita- 
tion of  cream  of  tartar. 

Why  is  zinc  carbonate  or  calcium  carbonate  used 
in  making  lactic  acid  by  fermenting  sugar?  In  order 
to  neutralize  the  acid,  for  in  the  presence  of  much 
lactic  acid  some  butyric  acid  is  formed. 

W^hy  must  the  temperature  of  lactic  acid  fermen- 
tation not  be  below  about  20°  C,  or  higher  than 
about  40°  C?  A  temperature  below  20°  C.  tends  to 
the  formation  of  acetic  acid,  and  one  above  40°  C. 
to  the  formation  of  butyric  acid. 

Why  is  lactic  acid  neutralized  w^ith  zinc  carbonate 
in  testing  it  for  glycerin?  The  zinc  lactate  formed  is 
insoluble  in  the  alcohol  used  to  dissolve  out  the 
glycerin. 

Wliy  is  sodium  nitrate  better  than  potassium 
nitrate  in  making  nitric  acid?  It  is  cheaper,  yields 
more  acid,  and  does  it  at  a  lower  temperature. 

Why  does  nitric  acid  sometimes  have  a  red  color? 
The  color  is  generally  due  to  nitrogen  tetroxide, 
which  is  a  decomposition  product  of  nitric  acid. 

Why  does  nitric  acid  give  a  yellow  color  when  ap- 
plied to  the  skin?  With  albuminoid  substances  it 
forms  the  yellow  xanthoprotein. 

Why  in  making  dilute  nitrohydrochloric  acid  does 


88  WHYS   IN    PHARMACY. 

the  U.  S.  p.  direct  that  strong  nitric  and  hydro- 
chloric acids  be  mixed,  and  then  this  mixture  dihited 
with  water,  instead  of  mixing  the  dilute  acids  them- 
selves? Chemical  reaction  takes  place  when  the 
strong  acids  are  mixed,  but  it  is  questionable  whether 
it  ensues  when  the  dilute  acids  are  used. 

Why  should  nitrohydrochloric  acid  be  kept  in 
bottles  not  more  than  half  full?  The  formation  and 
giving  off  of  gas  may  go  on  for  some  time,  and 
there  is  less  danger  of  bursting  the  bottle  when  it  is 
not  full. 

Why  should  the  temperature  not  go  over  190°  C. 
in  driving  off  nitric  acid  from  phosphoric  acid  in 
the  process  of  making  the  latter?  A  higher  heat 
tends  to  form  pyro-  and  meta-phosphoric  acids. 

Why  does  the  blackening  on  the  addition  of  silver 
nitrate  to  phosphoric  acid,  or  the  turbidity  on  add- 
ing mercuric  chloride,  indicate  phosphorous  acid? 
Phosphorous  acid  reduces  silver  nitrate  to  the  metallic 
condition,  and  reduces  mercuric  chloride  to  insoluble 
calomel. 

Why  should  nitrohydrochloric  acid  be  kept  away 
from  heat  and  light?  Nitrosyl  chloride  and  chlorine 
are  both  gases  and  light  changes  the  former  to  ni- 
trous and  hydrochloric  acids  and  the  latter  to  hydro- 
chloric acid. 

Why  in  titrating  phosphoric  acid,  does  it  take  only 
one  half  as  much  standard  potassium-hydroxide  solu- 
tion to  get  the  end  reaction  when  methyl  orange  is 
used  as  an  indicator  as  when  phenolphthalein   is 


CHEMICALS.  89 

employed?  Phenolphthalein  shows  a  neutral  reac- 
tion with  K2HPO4,  but  alkaUne  with  K3PO4,  while 
methyl  orange  shows  neutral  with  KH2PO4,  and 
alkaline  with  K2HPO4. 

Why  should  glacial  phosphoric  acid  be  dissolved 
in  water  without  heat  in  making  dilute  metaphos- 
phoric  acid,  N.  F.?  Because  heat  readily  changes  it 
to  pyro-  and  then  orthophosphoric  acid.  Light  and 
exposure  to  air  also  change  it. 

Why  is  "natural"  salicylic  acid  preferred  to  "syn- 
thetic" acid  by  many  physicians?  The  acid  made 
from  phenol  has  sometimes  been  found  to  be  con- 
taminated with  carbolic  and  creosotic  acids,  which 
are  more  depressing  and  poisonous  than  salicylic 
acid.  Synthetic  acid,  however,  can  generally  now 
be  relied  upon  for  purity. 

Why  does  salicylic  acid  sometimes  have  a  pink 
color?  It  is  due  to  the  presence  of  a  red  decom- 
position product. 

Why  is  sodium  carbonate  used  in  testing  salicylic 
acid  for  carbolic  acid  as  an  impurity?  Sodium  car- 
bonate converts  salicylic  acid  into  sodium  salicylate 
which  is  insoluble  in  ether.  Carbolic  acid,  remain- 
ing unaffected  by  the  sodium  salt,  can  be  removed 
with  ether. 

Why  does  sulphuric  acid  so  often  contain  arsenic? 
The  acid  is  largely  made  by  roasting  iron  pyrites, 
and  the  arsenic  which  occurs  in  the  pyrites  is  vola- 
tilized. 

Why  should  sulphuric  acid  be  poured  into  water 


90  WHYS   IN    PHARMACY. 

and  not  water  into  the  acid  in  mixing  the  two? 
There  is  less  heat  and  less  steam  generated  and  less 
danger  of  accident. 

Why  does  mixing  sulphuric  acid  and  water  pro- 
duce heat?  It  is  said  to  be  due  to  chemical  reaction 
and  contraction.  Hydrates  of  sulphuric  acid  are 
formed. 

Why  does  sulphuric  acid  when  dropped  on  such 
organic  matter  as  wood  blacken  it?  The  acid  ab- 
stracts the  elements  of  water  and  leaves  carbon. 

Why  is  lead  so  often  an  impurity  in  sulphuric 
acid?  The  acid  is  concentrated  in  lead  vats;  a 
little  lead  sulphate  is  formed  and  is  dissolved  by 
concentrated  acid  but  is  precipitated  when  the  acid 
is  diluted  with  water. 

Why  does  the  U.  S.  P.  state  that  aromatic  sul- 
phuric acid  should  contain  not  less  than  twenty  per 
cent,  of  absolute  acid  when  it  directs  that  111  cc.  of 
acid  be  used  in  making  1000  cc?  Ill  cc.  of  sul- 
phuric acid  weigh  202.686  grams  and  contain  187.484 
grams  of  absolute  acid.  The  specific  gravity  of 
aromatic  sulphuric  acid  is  given  as  0.933,  making 
1000  cc.  weigh  933  grams.  This  gives  about  20.09 
per  cent,  by  weight  of  acid. 

Why  does  aromatic  sulphuric  acid  gradually 
darken  on  keeping?  It  is  due  to  a  slow  reaction  of 
the  acid  with  the  aromatics. 

Why  does  the  addition  of  water  to  aromatic  sul- 
phuric acid  cause  a  precipitate?    Because  the  alcohol 


CHEMICALS.  91 

is  SO  diluted  that  the  oil  of  cinnamon  and  the  resin  of 
ginger  are  no  longer  soluble. 

Why  is  charcoal  preferred  to  copper  in  making 
sulphurous  acid?  Theoretically  none  of  the  acid  is 
wasted  with  charcoal,  carbon  dioxide,  sulphur  di- 
oxide and  water  being  formed.  In  using  copper 
some  of  the  acid  combines  with  the  copper  to  form 
copper  sulphate. 

Why  should  there  be  a  thistle  or  safety  tube  in 
the  sulphurous-acid  generator?  Because  on  remov- 
ing the  heat  there  is  a  contraction  and  the  water 
of  the  wash-bottle  may  be  sucked  back  into  the 
generator,  and  coming  in  contact  with  the  hot  mix- 
ture and  retort  will  cause  explosion  or  cracking  of 
the  retort. 

Why  is  sulphurous-acid  gas  washed  in  water?  To 
remove  sulphuric  acid  which  might  be  volatilized  in 
the  process. 

Why  should  the  water  employed  to  absorb  sul- 
phurous-acid gas  be  previously  boiled?  To  remove 
ammonia  and  free  oxygen  which  water  absorbs  on 
exposure  to  air  and  which  cause  the  deterioration  of 
the  acid. 

Why  does  the  gas  from  sulphurous  acid  blacken 
mercurous-nitrate  paper  and  not  lead-acetate  paper? 
It  reduces  mercurous  salts  to  metallic  mercury,  but 
does  not  reduce  lead  salts. 

Why  should  the  name  of  the  drug  from  which 
tannic  acid  comes  be  incorporated  in  the  title  of  the 
axiid?    Tannic  acid  from  different  sources  has  different 


92  WHYS   IN    PHARMACY. 

properties,  as  for  instance,  tannic  acid  from  nutgalls 
gives  a  blue-black  with  ferric  salts  while  the  acid 
from  oak-bark  gives  a  green-black. 


INORGANIC  COMPOUNDS. 

Why  is  it  better  in  making  dried  alum  to  let  it 
thoroughly  effloresce  at  a  temperature  below  80°  C. 
and  then  heat  to  drive  off  the  remaining  water 
than  it  is  to  heat  it  to  liquefaction  as  directed  by 
the  U.  S.  P.?  The  product  so  obtained  is  lighter, 
more  porous,  and  less  gritty.  Stirring  during  the 
heating  makes  it  more  dense. 

Why  is  it  necessary  to  have  a  decided  excess  of 
sodium  carbonate  in  making  aluminum  hydroxide, 
and  why  pour  the  alum  solution  into  the  carbonate 
solution  slowly  with  constant  stirring?  In  order  to 
decompose  all  of  the  aluminum  sulphate  and  to  have 
no  basic  sulphate  formed. 

Why  is  sodium  carbonate  used  instead  of  sodium 
hydroxide  in  making  aluminum  hydroxide?  Sodium 
hydroxide  combines  with  aluminum  hydroxide  to 
form  a  soluble  compound  while  the  carbonate  does 

not. 

Why  are  the  solutions  of  alum  and  sodium  car- 
bonate heated  just  before  mixing  in  making  aluminum 
hydroxide?  Chemical  reaction  takes  place  better  and 
a  more  dense  precipitate  is  formed  which  can  be 
washed  readily. 


CHEMICALS.  93 

Why  is  aluminum  hydroxide  dried  at  a  tempera- 
ture below  40°  C?  A  temperature  much  above  that 
will  drive  off  some  water  of  hydration,  forming  some 
aluminum  oxide  which  is  more  gritty. 

Why  does  a  solution  of  alum  effervesce  when  mixed 
with  a  solution  of  a  carbonate?  Alum  is  a  Httle 
acid  and  aluminum  hydroxide,  not  carbonate,  is 
formed,  liberating  carbon  dioxide. 

Why  in  making  ammonium  benzoate  should  the 
solution  of  ammonium  benzoate  be  kept  alkaline 
during  the  evaporation?  The  salt  is  easily  decom- 
posed by  heat,  and  ammonia  tends  to  prevent  decom- 
position. 

Why  does  ammonium  carbonate  become  white  and 
opaque  on  exposure  to  air?  It  loses  ammonia  and 
carbon  dioxide  (the  carbamate),  leaving  the  bicar- 
bonate. 

Why  does  the  U.  S.  P.  direct  the  use  of  ammonia 
water  in  testing  ammonium  iodide  for  bromide  and 
chloride  as  impurities?  If  an  iodide,  bromide,  and 
chloride  are  all  present  they  are  precipitated  by  silver 
nitrate  as  silver  compounds.  Silver  iodide  is  practi- 
cally insoluble  in  ammonia  water  while  the  bromide 
and  chloride  are  soluble.  The  iodide  can  be  filtered 
out,  and  the  adding  of  the  nitric  acid  to  the  filtrate 
precipitates  the  bromide  and  chloride. 

Why  is  a  slight  excess  of  antimony  oxide  used  in 
making  tartar  emetic?  So  as  to  neutralize  all  of  the 
cream  of  tartar,  an  excess  of  which  cannot  be  filtered 
out  as  readily  as  an  excess  of  antimony  oxide. 


94  WHYS   IN    PHARMACY. 

Why  is  sodium  bicarbonate  used  in  estimating 
tartar  emetic?  Reaction  takes  place  between  the 
iodine  and  tartar  emetic,  forming  hydriodic  acid, 
which  must  be  converted  into  a  neutral  salt  or  a 
reverse  action  takes  place. 

Why  is  hydrochloric  acid  added  to  silver  nitrate 
in  making  molded  silver  nitrate?  It  forms  a  small 
amount  of  silver  chloride  which  makes  the  fused 
sticks  more  tough  and  less  brittle. 

Why  is  care  necessary  in  mixing  silver  oxide  with 
organic  matter?  It  gives  up  its  oxygen  very  readily, 
forming  explosive  mixtures. 

Why  cannot  sodium  hydroxide  be  replaced  by 
ammonium  hydroxide  in  making  silver  oxide?  Am- 
monia forms  a  soluble  compound  with  silver  oxide. 

Why  is  sodium  bicarbonate  used  in  the  official 
method  of  estimating  arsenic  trioxide?  It  is  used  to 
neutralize  the  hydriodic  acid  formed,  for  in  an  acid 
solution  a  reverse  reaction  would  take  place,  hydri- 
odic acid  and  arsenic  acid  forming  iodine  and  arsen- 
ous  acid.  Sodium  bicarbonate  is  preferable  to  the 
normal  carbonate  or  the  hydroxide  because  the  end 
reaction  with  starch  is  more  delicate. 

Why  is  gold  and  sodium  chloride  recognized  by 
the  U.  S.  P.  instead  of  gold  chloride?  Gold  chloride 
keeps  better  when  mixed  with  sodium  chloride. 

Why  must  bismuth  subnitrate  be  boiled  with 
citric  acid  until  the  mixture  will  give  a  clear  solu- 
tion with  ammonia  water,  in  making  bismuth  citrate? 
Ammonia  forms  a  soluble  compound  with  bisnmth 


CHEMICALS.  95 

citrate,  but  not  with  the  subnitrate.  If  a  clear  solu- 
tion with  ammonia  is  not  obtained,  bismuth  sub- 
nitrate  is  not  all  changed. 

Why  should  a  large  excess  of  ammonia  water  be 
avoided  in  making  bismuth  and  ammonium  citrate? 
Heating  bismuth  citrate  with  a  large  excess  of  am- 
monia water  tends  to  form  the  insoluble  bismuth 
hydroxide. 

Why  is  it  customary  in  making  bismuth  subnitrate 
to  convert  the  bismuth  nitrate  into  the  carbonate 
and  then  back  into  the  nitrate?  To  get  rid  of 
arsenic. 

Why  in  making  precipitated  calcium  carbonate 
are  solutions  of  calcium  chloride  and  sodium  car- 
bonate hot  wnen  mixed?  Heat  makes  the  precipi- 
tated calcium  carbonate  denser  and  more  easily 
washed  free  from  the  sodium  chloride. 

Why  does  lime  produce  heat  when  mixed  with 
water?  Chemical  reaction  takes  place,  forming  cal- 
cium hydroxide. 

Why  does  chlorinated  lime  become  moist  on  ex- 
posure to  air?  It  contains  calcium  chloride,  which 
is  hygroscopic. 

Why  should  heat  not  exceed  25°  C.  in  making 
chlorinated  lime?  Heat  above  that  causes  the  forma- 
tion of  calcium  chlorate. 

Why  is  not  all  of  the  chlorine  in  chlorinated  lime 
available?  Part  of  it  is  combined  as  calcium  chlo- 
ride which  is  a  stable  compound  and  not  decomposed 
by  dilute  or  weak  acids  as  calcium  hypochlorite  is. 


96  WHYS   IN   PHARMACY. 

Why  is  prepared  chalk  recognized  by  the  U.  S.  P. 
when  the  purer  calcium  carbonate  is  official?  Pre- 
pared chalk  is  less  crystalline,  smoother,  softer,  more 
adhesive,  and  better  for  internal  administration. 

Why  is  starch  used  in  making  sulphurated  lime? 
It  is  not  necessary,  but  aids  in  the  reduction  of  the 
sulphate. 

Why,  in  the  U.  S.  P.  method  of  estimating  sul- 
phurated lime,  should  ammonia  water  give  no  color 
when  added  to  the  filtrate  from  the  mixture  of  sul- 
phurated lime  and  copper  sulphate?  If  the  full 
amount  of  sulphide  is  in  the  sulphurated  lime  all 
of  the  copper  will  be  precipitated  and  none  will 
pass  into  the  filtrate.  If  copper  passes  into  the 
filtrate  it  will  give  a  blue  color  when  ammonia  water 
is  added. 

Why  is  nitric  acid  used  to  wash  out  sulphuric  acid 
from  chromium  trioxide?  Nitric  acid  does  not  dis- 
solve much  of  the  chromium  trioxide,  does  not  cause 
chemical  reaction,  and  can  itself  be  removed  by 
heating. 

Why  does  the  color  of  chromium  trioxide  vary? 
On  account  of  the  presence  or  absence  of  sulphuric 
acid,  that  which  contains  sulphuric  acid  having  more 
of  a  scarlet  color. 

Why  should  asbestos  or  glass-wool  be  used  for  filter- 
ing solutions  of  chromium  trioxide?  Paper,  cotton, 
or  anything  capable  of  being  oxidized  would  be 
affected  and  the  acid  reduced. 

Why  is  sodium  bicarbonate  used  instead  of  sodium 


CHEMICALS.  97 

carbonate  in  making  saccharated  ferrous  carbonate? 
The  carbon  dioxide  which  is  liberated  protects  the 
ferrous  salt  from  oxidation  to  some  extent. 

Why  is  sodium  bicarbonate  dissolved  in  water 
'^not  exceeding  50°  C. ''  in  making  saccharated  car- 
bonate of  iron?  A  higher  temperature  decomposes 
the  bicarbonate,  driving  off  the  carbon  dioxide,  which 
is  wanted  to  protect  the  ferrous  salt. 

Why  is  hot  water  used  in  washing  ferrous  car- 
bonate in  making  saccharated  carbonate  of  iron? 
Hot  water  dissolves  sodium  sulphate  better  and  is 
free  from  absorbed  oxygen  which  would  otherwise 
tend  to  oxidize  the  iron. 

Why  does  the  U.  S.  P.  method  of  estimating 
chloride  of  iron  not  always  show  all  of  the  iron 
present?  The  official  method  estimates  only  the 
iron  in  the  ferric  condition.  Ferrous  iron  does  not 
liberate  iodine  from  potassium  iodide. 

Why  is  excess  of  citric  acid  to  be  avoided  in  making 
scale  citrate  of  iron?  Acid  keeps  the  salt  tough  and 
sticky  so  that  it  adheres  to  the  glass  on  which  it  is 
spread  and  does  not  scale. 

Why  is  the  solution  of  citrate  of  iron  evaporated 
at  a  temperature  below  60°  C.  in  making  citrate  of 
iron?  A  higher  temperature  causes  a  reduction  of 
the  iron. 

Why,  in  testing  ferric  citrate  for  citric  acid,  is  the 
filtrate  heated  with  calcium  chloride  in  order  to  get 
a  precipitate  when  heat  usually  tends  to  dissolve 
salts?    Calcium   citrate   is  formed,  and   like   many 


98  WHYS   IN   PHARMACY. 

calcium  salts  it  is  less  soluble  in  hot  water  than  in 
cold. 

Why  is  ferric  citrate  preferred  to  citrate  of  iron  and 
ammonia  in  making  pills?  It  is  not  as  hygroscopic 
and  the  pills  retain  their  form  better. 

Why  does  the  U.  S.  P.  not  give  a  chemical  for- 
mula for  citrate  of  iron?  Because  the  water  of 
hydration  varies,  although  a  formula  might  be  given 
with  limits,  since  the  Pharmacopoeia  requires  the 
salt  to  contain  a  nearly  definite  amount  of  iron. 

Why  are  some  samples  of  iron  and  ammonium 
citrate  more  hygroscopic  than  others?  The  larger 
the  amount  of  ammonium  salt  present  the  more 
hygroscopic  it  is. 

Why  is  one  half  of  the  tartaric  acid  neutralized 
with  ammonia  and  then  the  balance  of  the  acid 
added  to  this,  in  making  iron  and  ammonium  tar- 
trate (1890)?  This  procedure  makes  ammonium  bi- 
tartrate,  to  which  is  added  later  the  ferric  hydroxide 
forming  a  double  compound. 

Why  should  care  be  used  not  to  get  in  an  excess 
of  ammonia  in  making  soluble  citrate  of  iron  and 
quinine  (1890)?  Ammonia  precipitates  the  quinine 
but  not  the  iron  in  the  presence  of  ammonium  citrate. 

Why  should  citrate  of  iron  and  strychnine  not  be 
prescribed  in  solution?  According  to  Squibb  a  de- 
composition takes  place  in  a  few  hours  and  strych- 
nine is  precipitated,  rendering  the  mixture  dangerous. 

Why  is  ferric-ammonium  sulphate  used  by  the 
N.  F.  in  making  ferric  hypophosphite,  instead  of  oiw 


CHEMICALS.  99 

of  the  more  common  iron  salts?  It  is  more  nearly- 
neutral  and  consequently  will  give  a  larger  yield. 
Moreover,  in  an  acid  solution  ferric  hypophosphite 
changes  to  ferrous  phosphate. 

Why  is  sugar  of  milk  added  to  the  solution  of  fer- 
rous iodide  before  evaporating  in  making  saccha- 
rated  iodide  of  iron  (1890)?  To  prevent  oxidation 
and  the  liberation  of  iodine. 

Why  is  a  heated  mortar  used  in  powdering  the 
residue  of  iodide  of  iron  and  milk  sugar?  The  resi- 
due is  hygroscopic  and  the  heated  mortar  tends  to 
prevent  the  absorption  of  moisture. 

Why  is  reduced  iron  added  to  the  ferrous  iodide 
in  making  saccharated  iodide  of  iron  (1890)?  It 
combines  with  any  iodine  that  may  be  liberated  from 
the  iodide  by  the  air. 

Why  should  a  solution  of  ferric  salt  always  be 
poured  into  ammonia,  and  not  ammonia  into  the 
iron  solution,  in  making  ferric  hydroxide?  Because 
by  adding  the  iron  to  the  ammonia  the  latter  is  in 
excess  and  the  ferric  hydroxide  is  formed,  while  if 
the  ammonia  is  added  to  the  iron  the  latter  is  in 
excess  and  a  basic  salt  is  precipitated. 

Why  should  solution  of  ferric  sulphate  and  am- 
monia be  cold  and  well  diluted  before  mixing,  in 
making  ferric  hydroxide?  To  prevent  the  formation 
of  a  basic  compound.  Several  oxyhydrates  may  be 
formed,  and  the  more  basic  the  hydrate,  the  less 
soluble  it  is  in  acids. 

Why  is  ammonium  hydroxide  preferable  to  sodium 


100  WHYS   IN   PHARMACY. 

hydroxide  in  making  ferric  hydroxide?  Ammonium 
sulphate  and  the  excess  of  ammonium  hydroxide  are 
more  easily  washed  out  than  the  corresponding  so- 
dium compounds. 

Why  is  ferric  hydroxide  washed  by  decantation? 
It  is  bulky  and  gelatinous,  not  readily  washed  on  the 
filter,  and  is  less  liable  to  become  partially  dry  and 
changed  to  oxide. 

Why  must  the  soluble  phosphate  and  the  soluble 
pyrophosphate  of  iron  be  well  protected  from  the 
light?    Light  renders  them  darker  and  less  soluble. 

Why  do  some  persons  think  that  soluble  phos- 
phate of  iron  and  soluble  pyrophosphate  of  iron  are 
chemical  compounds?  Because,  if  they  are  mere 
mixtures,  any  salts  that  would  be  present  would  not 
give  the  green  color;  the  color  is  therefore  due  to  a 
new  compound. 

Why  does  ferrous  sulphate  frequently  contain  a 
little  sulphuric  acid?  It  is  not  so  readily  oxidized 
when  acid  is  present. 

Why  does  the  official  method  of  estimating  ferrous 
sulphate  not  always  estimate  all  of  the  iron  present? 
Ferrous  sulphate  generally  contains  some  ferric  iron, 
and  in  the  ferric  condition  iron  does  not  reduce 
potassium  permanganate. 

Why,  in  making  dried  sulphate  of  iron,  is  ferrous 
sulphate  allowed  to  effioresce  at  a  temperature  of 
40°  C.  previous  to  heating  on  a  water-bath?  If 
heated  at  once  on  the  water-bath  the  salt  would  dis- 
solve in  its  water  of  crystallization;    it  would  be 


CHEMICALS.  ,  '\  iJ^'\  XOV  ,;  '\ ; 

much  harder  to  drive  off  the  water  and  the  residue 
would  be  more  gritty  and  granular. 

Why  is  not  all  the  water  removed  in  making  dried 
sulphate  of  iron?  The  high  heat  necessary  to  remove 
all  the  water  would  probably  cause  more  or  less 
decomposition  of  the  salt. 

Why  is  sulphuric  acid  used  in  granulating  ferrous 
sulphate?  Ferrous  sulphate  almost  always  contains 
some  oxysalt  which  does  not  dissolve,  and  sulphuric 
acid  brings  it  into  solution. 

Why  is  alcohol  used  in  making  granulated  ferrous 
sulphate?  It  washes  out  the  water  and  acid,  dis- 
solving the  ferric  salt  without  dissolving  the  ferrous. 
The  ferrous  sulphate  is  dried  in  an  atmosphere  of 
alcohol  which  prevents  oxidation. 

Why  is  granulated  ferrous  sulphate  preferably  dried 
in  the  sunlight?  As  light  has  a  reducing  effect  on 
iron  salts,  there  is  less  danger  of  oxidation  of  the 
ferrous  salt. 

Why  is  reduced  iron  sometimes  called  '^iron  by 
hydrogen"?  In  making  it  hydrogen  is  passed  over 
red  hot  ferric  oxide  and  combines  with  the  oxgyen 
leaving  metallic  iron. 

Why  is  the  current  of  hydrogen  passed  over  the 
iron  even  after  it  is  all  reduced?  To  prevent  air 
coming  in  contact  with  the  iron  while  it  is  hot,  in 
which  condition  it  would  absorb  oxygen. 

Why  does  reduced  iron  frequently  contain  an 
oxide?  In  making  it,  if  a  low  red  heat  is  used,  the 
oxide  is  not  all  decomposed,  and  if  a  higher  heat  is 


102  WHYS   IN   PHARMACY. 

used  a  more  dense  and  less  desirable  product  is 
formed.  If  the  iron  is  left  in  a  moist  atmosphere  it 
absorbs  oxygen. 

Why  is  manganese  dioxide  sometimes  added  to 
mercuric  sulphate  and  sodium  chloride  before  sub- 
liming in  making  mercuric  chloride?  To  prevent  the 
formation  of  mercurous  chloride. 

Why  is  it  that  an  aqueous  solution  of  mercuric 
chloride  is  acid  to  litmus  but  becomes  neutral  on 
adding  sodium  chloride?  It  may  be  on  account  of 
forming  a  new  double  salt  which  is  neutral. 

Why  should  mercuric  chloride,  particularly  when 
in  solution,  be  protected  from  the  light?  Light  re- 
duces it  slowly  to  mercurous  chloride.  This  is  pre- 
vented to  some  extent  by  the  presence  of  an  alkali 
chloride. 

Why  does  the  commercial  mercuric  chloride  not 
always  give  a  clear  solution  with  water?  It  fre- 
quently contains  a  little  mercurous  chloride. 

Why  is  ammonia  used  in  testing  mercuric  chloride 
for  arsenic  as  an  impurity?  The  mercury  and  ar- 
senic are  first  converted  into  the  sulphides  and  the 
arsenous  sulphide  forms  the  soluble  ammonium  sulph- 
arsenite  which  is  subsequently  decomposed  by  hy- 
drochloric acid,  precipitating  the  arsenous  sulphide. 

Why  is  the  condenser  kept  at  a  temperature  near 
that  of  the  subliming  point  of  mercuric  chloride  in 
making  mercuric  chloride  and  considerably  below  that 
of  mercurous  chloride  in  making  mercurous  chloride? 
It  is  desirable  to  have  mercuric  chloride  in  the  form 


CHEMICALS.  103 

of  masses  and  mercurous  chloride  in  powder  so  that 
they  can  be  more  easily  distinguished.  When  the 
temperature  of  the  condenser  is  near  the  subliming- 
point  of  a  substance  that  substance  will  condense 
in  the  form  of  a  mass,  while  if  the  temperature  of 
the  condenser  is  much  below  the  subliming-point 
the  substance  will  condense  as  a  powder. 

Why  is  a  jet  of  steam  introduced  into  the  receiv- 
ing chamber  in  making  calomel?  It  makes  the  calo- 
mel fine  and  soft,  and  dissolves  out  any  mercuric 
chloride  formed. 

Why  should  calomel  not  be  triturated  hard?  It  is 
decomposed  slightly,  forming  metallic  mercury  which 
darkens  it,  and  mercuric  chloride  which  makes  it 
more  active. 

Why  does  the  color  of  calomel  vary  even  when 
pure?    The  finer  the  powder  the  more  yellow  it  is. 

Why  should  calomel  be  kept  in  amber-colored 
bottles?  Light  slowly  decomposes  it,  forming  metal- 
lic mercury  and  mercuric  chloride. 

Why  is  an  excess  of  mercury  used  in  making  yel- 
low iodide  of  mercury?  Because  if  the  nitric  acid  is 
in  excess  some  mercuric  salt  is  formed. 

Why  should  the  nitric  acid  and  metallic  mercury  be 
kept  cool  in  making  the  yellow  iodide  of  mercury? 
Heat  tends  to  produce  mercuric  nitrate. 

Why  is  a  little  nitric  acid  added  to  the  watery 
solution  of  mercurous  nitrate  in  making  yellow  iodide 
of  mercury?    To  prevent  the  formation  of  a  basic  salt. 

Why,  in  making  this  salt,  is  the  solution  of  potas- 


104  WHYS   IN   PHARMACY. 

sium  iodide  poured  into  the  solution  of  mercurous 
nitrate  instead  of  the  mercury  into  the  iodide?  If 
the  mercury  is  poured  into  the  potassium  iodide  solu- 
tion the  latter  is  in  excess  at  first,  at  least,  and  in  this 
condition  decomposes  the  mercurous  iodide  which  is 
first  formed,  giving  mercuric  iodide  and  metallic 
mercury.  The  mercuric  iodide  further  combines 
with  potassium  iodide  to  form  a  soluble  double  salt. 

Why  is  it  well  to  wash  mercurous  iodide  with 
alcohol?  To  dissolve  out  any  mercuric  iodide  that 
may  be  present. 

Why  must  mercurous  iodide  be  protected  from 
the  light?  Light  decomposes  it,  forming  mercuric 
iodide  and  metallic  mercury,  the  latter  darkens  it. 

Why  is  much  of  the  mercurous  iodide  green  instead 
of  yellow?  Because  it  contains  some  finely  divided 
metallic  mercury.  Mercury  finely  divided  has  a 
bluish  color,  and  this  with  the  yellow  gives  a  green. 

Why  does  the  U.  S.  P.  direct  the  solutions  of  mer- 
curic chloride  and  potassium  iodide  to  be  poured 
simultaneously  into  water  in  making  mercuric  iodide? 
Because  if  either  solution  is  poured  into  the  other  a 
soluble  double  compound  is  formed. 

Why  does  the  formula  call  for  a  slight  excess  of 
potassium  iodide  in  making  mercuric  iodide?  Be- 
cause it  is  desirable  to  have  all  the  mercuric  chloride 
decomposed,  even  though  there  is  a  little  loss  in  sub- 
sequent washings. 

Why  is  the  solution  of  mercuric  chloride  poured 
into  the  solution  of  sodium  hydroxide  and  not  the 


CHEMICALS.  105 

hydroxide  into  the  mercury?  Having  the  alkaU  in 
excess,  the  yellow  mercuric  oxide  is  precipitated, 
while  if  the  mercury  is  in  excess  the  red-brown  oxy- 
chloride  of  mercury  is  precipitated. 

Why  are  the  solutions  of  mercuric  chloride  and 
sodium  hydroxide  well  diluted  before  mixing,  in 
making  yellow  oxide  of  mercury?  To  avoid  the  red- 
brown  oxy chloride.  For  the  same  reason  the  mercury 
solution  must  be  added  slowly  with  constant  stir- 
ring to  the  alkali  solution. 

Why  is  the  mixture  of  these  solutions  allowed  to 
stand  for  an  hour?  To  complete  the  reaction  and 
decompose  any  oxychloride  formed. 

Why  must  the  sodium  hydroxide  be  free  from  car- 
bonate? The  carbonate  forms  a  basic  compound 
which  is  more  red. 

Why  does  the  U.  S.  P.  direct  a  temperature  of 
about  30°  C?  The  higher  the  temperature  the  quicker 
will  be  the  reaction,  but  a  temperature  above  30°  C. 
tends  to  the  formation  of  a  reddish  salt. 

Why  should  mercuric  oxide  be  washed  until  the 
washings  give  no  turbidity  with  a  solution  of  mer- 
curic chloride?  So  long  as  a  turbidity  results  there 
is  some  sodium  hydroxide  present. 

Why  should  yellow  oxide  of  mercury  be  protected 
from  the  light?  Light  decomposes  it,  forming  metal- 
lic mercury  and  oxygen  and  the  metallic  mercury 
causes  it  to  darken.  It  changes  more  readily  than 
the  red  on  account  of  its  greater  fineness. 

Why  was  the  yellow  subsulphate  of  mercury  called 


106  WHYS   IN   PHARMACY. 

turpeth  mineral?     It  is  a  mineral  substance  some- 
what resembling  powdered  turpethium  in  appearance. 

Why  is  nitric  acid  used  in  making  yellow  subsul- 
phate  of  mercury  (1890)?  Because  it  assists  the 
formation  of  mercuric  sulphate. 

Why  is  mercuric  sulphate  solution  evaporated  to 
dryness  and  heated  on  a  sand-bath?  To  get  rid  of 
the  excess  of  acid. 

Why  is  mercuric  sulphate  added  to  boiling  water 
in  making  yellow  subsulphate  of  mercury?  Because 
this  causes  decomposition  and  the  formation  of  the 
basic  compound. 

Why  is  an  excess  of  ammonia  used  in  making  am- 
moniated  mercury,  and  why  is  the  precipitate  washed 
with  water  containing  ammonia?  Because  there  is 
liability  of  forming  a  yellow  basic  salt  unless  am- 
monia is  present. 

Why  is  the  solution  of  mercuric  chloride  filtered 
before  pouring  into  ammonia  in  making  ammoniated 
mercury?  To  remove  any  calomel  which,  if  present, 
would  give  a  black  compound  with  ammonia. 

Why  should  ammoniated  mercury  not  be  washed 
with  an  excessive  amount  of  water  or  dried  with 
heat  or  exposed  to  light?  All  tend  to  change  it  to 
a  yellow  basic  compound. 

Why  is  chalk  made  into  a  mass  with  water  before 
mixing  with  the  finely  divided  mercury  in  making 
mercury  with  chalk?  If  an  attempt  were  made  to 
mix  the  dry  carbonate  with  the  mixture  of  honey 
and  divided  mercury  it  would  become  so  drv  that 


.     CHEMICALS.  107 

the  mixing  would  cause  the  union  of  the  small  glob- 
ules of  mercury. 

Why  should  mercury  with  chalk  be  powdered  with- 
out trituration?  Rubbing  causes  the  small  particles 
of  mercury  to  unite  to  form  larger  globules. 

Why  should  mercury  with  chalk  be  protected  from 
the  air  and  light?  Metallic  mercury  when  finely 
divided  is  easily  oxidized  and  becomes  darker. 

Why  is  sodium  carbonate  preferred  to  potassium 
carbonate  in  making  magnesium  carbonate?  It  is 
cheaper  and  purer;  and  the  sodium  sulphate  is 
easier  to  wash  out  than  the  potassium  sulphate. 

Why  does  magnesium  carbonate  vary  in  com- 
position? The  extra  heat  used  in  making  the 
heavy  carbonate  drives  off  more  of  the  carbon  di- 
oxide. 

Why  does  magnesium  carbonate  vary  in  density? 
The  heavy  salt  is  made  by  mixing  hot  concentrated 
solutions  of  magnesium  sulphate  and  sodium  car- 
bonate, and  the  light  salt  by  mixing  cold  dilute  solu- 
tions. 

Why  does  heat  aid  in  the  precipitation  of  mag- 
nesium carbonate  from  a  mixture  of  the  solutions  of 
magnesium  sulphate  and  sodium  carbonate?  Heat 
drives  off  the  carbon  dioxide,  which  otherwise  re- 
mains and  holds  some  of  the  magnesium  in  solution 
as  the  bicarbonate. 

Why  should  the  heating  of  magnesium  carbonate 
not  be  continued  too  long,  nor  allowed  to  get  above 
a  dull  red  heat,  in  making  magnesia?    Both  con- 


108  WHYS   IN   PHARMACY. 

clitions  tend  to  make  magnesia  lumpy  and  granular 
and  less  readily  soluble  in  acids. 

Why  are  some  magnesium  oxides  much  lighter 
than  others?  Heavy  magnesia  is  made  by  calcining 
heavy  magnesium  carbonate,  while  the  light  is  made 
by  calcining  the  light  magnesium  carbonate.  High 
heat,  pressure  of  the  carbonate  before  calcining, 
moistening  the  carbonate  before  calcining,  heavy 
trituration  of  magnesia,  all  have  a  tendency  to  render 
the  magnesia  more  dense. 

Why,  in  mixing  magnesia  with  water,  should  the 
magnesia  be  added  to  a  large  excess  of  water?  A 
small  amount  of  water  makes  the  magnesia  hard, 
gritty,  and  lumpy,  while  a  large  amount  of  water 
gives  a  smooth  gelatinous  hydroxide. 

Why  does  one  part  of  magnesia  with  fifteen  parts 
of  water  give  a  solid  mass?  Water  is  taken  up  to 
form  the  hydroxide. 

Why  is  it  generally  necessary  to  add  a  little  acetic 
acid  to  get  a  clear  solution  of  lead  acetate  in  water? 
On  exposure  to  air  lead  acetate  absorbs  carbon  di- 
oxide and  forms  the  insoluble  lead  carbonate  and 
the  acid  dissolves  this. 

Why  should  the  solution  of  lead  acetate  be  added 
to  potassium  iodide  in  making  lead  iodide?  If  the 
iodide  is  added  to  the  lead  an  oxy iodide  is  formed. 

Why  is  it  necessary  to  have  free  nitric  acid  present 
in  crystallizing  lead  nitrate?  If  it  is  not  present 
the  crystals  will  be  more  or  less  opaque. 

Why  does  lead  oxide  vary  in  color?    The  color 


CHEMICALS.  109 

depends  on  the  temperature  of  oxidation  and  the  rapid- 
ity of  coohng,  being  more  yellow  when  cooled  rapidly. 

Why  is  a  warm  mortar  directed  in  making  potassa 
with  lime?  Potassa  is  hygroscopic,  and  heat  prevents 
the  absorption  of  moisture  while  mixing. 

Why  should  a  higher  heat  than  just  enough  to 
cause  a  chemical  reaction  be  avoided  in  making  sul- 
phurated potassa?  High  heat  tends  to  the  forma- 
tion of  potassium  sulphate. 

Why  must  sulphurated  potash  be  protected  from 
air?  To  prevent  the  absorption  of  moisture  and 
oxygen  which  will  change  it  to  a  sulphate. 

Why  is  acetic  acid  used  in  excess  in  making  potas- 
sium acetate?  If  the  alkali  is  in  excess  the  salt  is 
apt  to  be  colored. 

Why  is  potassium  acetate  heated  in  estimating  it? 
Heat  converts  it  into  the  carbonate,  which  can  be 
estimated  by  a  standard  acid  solution. 

Why  is  methyl  orange  preferable  to  phenolphtha- 
lein  and  most  other  indicators  in  titrating  a  carbon- 
ate?   It  is  not  affected  by  carbon  dioxide. 

Why  is  potassium  bicarbonate  purer  than  the 
normal  carbonate?  The  carbonate  is  quite  strongly 
alkaline  and  dissolves  silica.  In  passing  carbon  di- 
oxide into  a  solution  of  carbonate,  it  changes  the 
normal  carbonate  to  the  bicarbonate,  precipitates 
the  silica,  and  the  bicarbonate  can  then  be  crystallized. 

Why  is  charcoal  used  in  making  potassium  bro- 
mide when  it  is  made  by  the  direct  combination  of 
bromine  and  potassium  hydroxide?     While  most  of 


110  WHYS   IN  PHARMACY. 

the  bromine  combines  with  the  potassium  to  form 
potassium  bromide,  about  a  sixth  of  it  forms  potas- 
sium bromate;  and  heating  the  bromate  with  char- 
coal reduces  it  to  the  bromide. 

Why  does  the  addition  of  dilute  sulphuric  acid 
to  potassium  bromide,  resulting  in  the  getting  of 
bromine,  indicate  the  presence  of  a  bromate,  since 
dilute  sulphuric  acid  does  not  liberate  bromine  from 
either  a  bromide  or  a  bromate?  Sulphuric  acid  liber- 
ates hydrobromic  acid  and  bromic  acid,  and  these 
react  on  each  other,  liberating  bromine  from  both. 

Why  does  the  U.  S.  P.  allow  potassium  bromide  to 
be  slightly  alkaline?  The  presence  of  a  small  amount 
of  carbonate  prevents  the  liberation  of  bromine. 

Why,  in  estimating  a  chloride  as  an  impurity  in 
potassium  bromide,  does  the  U.  S.  P.  direct  that  it 
should  not  require  more  than  25.85  cc.  of  N/10 
silver-nitrate  solution  to  produce  a  red  color?  A 
red  color  is  produced  only  after  all  of  the  bromide  and 
chloride  are  precipitated.  Potassium  chloride  takes 
more  silver  nitrate  for  precipitation  than  the  same 
weight  of  potassium  bromide,  consequently  the  Phar- 
macopoeia limits  the  amount  of  silver. 

Why  does  potassium  carbonate  occur  in  granular 
form?  It  is  deliquescent  and  not  easily  crystallized 
and  in  the  granular  form  it  is  more  permanent. 

Why  is  potassium  chlorate  heated  with  aluminum 
and  potassium  hydroxide  in  testing  it  for  a  nitrate 
as  an  impurity?  The  chlorate  and  nitrate  are  re- 
duced.    Ammonia  is  formed  from  the  nitrate. 


CHEMICALS.  Ill 

Why  does  the  getting  of  a  precipitate  by  adding 
acetic  acid  to  potassium  citrate  indicate  the  presence 
of  a  tartrate?  If  the  tartrate  is  present  it  is  there 
in  the  form  of  a  normal  salt  and  is  soluble.  Acetic 
acid  converts  it  into  the  bitartrate,  which  is  spar- 
ingly soluble. 

Why,  in  estimating  potassium  cyanide,  does  the 
amount  of  silver  nitrate  solution  taken  to  produce 
a  permanent  precipitate  represent  only  one  half  of 
the  silver  solution  necessary  to  make  pure  silver  cya- 
nide? One  molecule  of  potassium  cyanide  combines 
with  one  of  silver  cyanide  to  form  the  insoluble  silver 
cyanide.  This  then  combines  with  another  molecule 
of  potassium  cyanide  to  form  a  soluble  double  com- 
pound. It  is  only  after  all  of  the  potassium  cyanide 
is  taken  up  in  this  double  compound  that  the  addi- 
tion of  silver  nitrate  causes  a  permanent  precipitate. 

Why  is  potassium  and  sodium  tartrate  called 
Rochelle  salt?  It  was  first  prepared  at  Rochelle, 
France. 

Why  does  the  addition  of  acetic  acid  to  a  strong 
solution  of  Rochelle  salt  produce  a  precipitate?  The 
acid  combines  with  the  sodium  and  liberates  the 
potassium  acid  tartrate  which  is  not  very  soluble. 

Why  is  potassium  bicarbonate  used  rather  than 
the  normal  carbonate  in  making  potassium  hydrox- 
ide?    It  is  purer. 

AVhy  is  the  solution  of  potassium  hydroxide  evapo- 
rated in  metallic  vessels?  Because  glass  or  earthen- 
ware is  attacked  by  alkalies,  forming  soluble  silicates. 


112  WHYS    IN    PHARMACY. 

Why  are  green  glass  bottles  better  than  flint 
bottles  for  containing  potassium  hydroxide?  The 
green  glass  is  not  so  readily  attacked  as  the  flint. 

Why  should  a  solution  of  potassium  hypophos- 
phite  be  evaporated  at  a  temperature  below  its 
boiling-point?  At  the  boiling-point  of  the  solution 
there  is  danger  of  decomposition  and  also  danger 
of  explosion. 

Why  is  a  solution  of  ammonium  molybdate  of 
no  service  in  testing  potassium  hypophosphite  for 
a  phosphate  as  an  impurity?  The  ammonium 
molybdate  solution  contains  free  nitric  acid  which 
would  oxidize  the  hypophosphite  to  a  phosphate, 
and  thus  a  test  would  be  obtained  though  a  phos- 
phate may  not  have  been  there  originally. 

Why  in  testing  potassium  hypophosphite  for  a 
chloride  is  the  hypophosphite  first  heated  with 
nitric  acid?  To  oxidize  the  hypophosphite  to  a 
phosphate  so  that  it  will  not  reduce  the  silver  nitrate 
and  interfere  with  the  test. 

Why  is  it  best  to  evaporate  a  solution  of  potassium 
iodide  at  about  50°  C.  to  60°  C.  in  crystallizing  the 
salt?  Larger  crystals  are  formed  than  if  a  higher 
temperature  were  used  and  the  solution  does  not 
creep  over  the  edges  of  the  dish  so  much  as  it  does 
at  a  lower  temperature. 

Why  is  potassium  iodide  sometimes  whiter  and 
more  opaque  than  it  is  at  others?  Potassium  car- 
bonate tends  to  make  it  whiter. 

Why  is  potassium  carbonate  often  an  impurity 


CHEMICALS.  113 

in  potassium  iodide?  It  tends  to  prevent  the  libera- 
tion of  iodine. 

Why  is  the  httle  amount  of  potassium  carbonate 
that  is  left  in  objectionable?  It  makes  the  iodide 
more  hygroscopic  and  also  alkaline,  so  that  a  solu- 
tion of  it  may  cause  precipitation  with  metallic 
and  alkaloidal  salts  when  a  pure  iodide  would 
not. 

Why  does  dilute  sulphuric  acid  liberate  iodine 
from  potassium  iodide  if  it  is  contaminated  with 
iodate?  Sulphuric  acid  liberates  hydriodic  and 
iodic  acids,  and  these  react  on  each  other,  liberating 
iodine. 

Why  in  testing  potassium  iodide  for  a  nitrate  is 
the  nitrate  changed  to  ammonia  instead  of  making 
the  test  with  ferrous  sulphate  and  sulphuric-acid? 
Concentrated  sulphuric  acid  liberates  iodine  which 
would  interfere  with  the  test. 

Why  does  the  U.  S.  P.  direct  that  not  more  than 
30.8  cc.  of  decinormal  silver-nitrate  solution  be  used 
for  0.5  gram  of  potassium  iodide,  in  testing  this  salt? 
More  would  indicate  contamination  with  a  bromide 
or  chloride. 

Why  is  asbestos  used  in  filtering  a  solution  of 
potassium  permanganate?  Asbestos  is  not  acted  on 
like  filter-paper,  cotton,  or  an  organic  medium. 

Why  is  sodium  carbonate  allowed  to  effloresce 
before  heating,  in  making  dried  sodium  carbonate? 
Because,  if  heated  at  first,  the  salt  dissolves  in  the 
water   of  crystallization;    the   water   is   driven   off 


114  WHYS   IN   PHARMACY. 

with  difficulty,  and  the  product  thus  obtained  is 
granular  instead  of  being  smooth. 

Why  is  commercial  sodium  chloride  hygroscopic? 
It  often  contains  a  little  magnesium  chloride  or  cal- 
cium chloride,  either  of  which  is  deliquescent. 

Why  does  sodium  hydroxide  produce  heat  when 
dissolved  in  water?  A  large  number  of  hydroxides 
are  formed  and  the  chemical  reactions  cause  the 
heat. 

Why  does  sodium  hydroxide  sometimes  appear 
efflorescent?  Caustic  soda  is  deliquescent  and  also 
absorbs  carbon  dioxide  from  the  air.  When  it  has 
absorbed  considerable  carbon  dioxide  the  carbonate 
formed  becomes  efflorescent. 

Why  does  sodium  iodide  produce  heat  when  dis- 
solved in  water,  while  the  corresponding  potassium 
iodide  does  not?  Official  sodium  iodide  is  anhydrous 
and  takes  up  two  molecules  of  water  of  crystallization. 

Why  is  the  common  method  of  detecting  a  nitrate 
by  means  of  ferrous  sulphate  and  sulphuric  acid  not 
used  in  testing  sodium  iodide  for  a  nitrate?  Strong 
sulphuric  acid  liberates  iodine  from  an  iodide  and 
this  would  interfere  with  the'  test. 

Why  is  heat  used  in  making  sodium  sulphocar- 
bolate?  Heat  forms  a  para-salt,  which  is  official. 
In  the  cold  the  ortho-salt  is  formed. 

Why  is  sodium  salicylate  usually  slightly  acid? 
A  little  free  acid  is  left  in  it  because  it  does  not 
turn  red  as  quickly  when  the  salt  is  a  little  acid  as 
when  it  is  neutral  or  alkaline. 


CHEMICALS.  11 


K 


Why  is  cotton  or  glass-wool  better  than  filter- 
paper  for  filtering  a  solution  of  a  salicylate?  Filter- 
paper  often  contains  a  little  iron  which  gives  a  pink 
or  red  color  with  a  salicylate. 

Why  is  the  receiving-chamber  not  allowed  to  get 
hotter  than  about  110°  C.  in  making  sublimed  sul- 
phur? At  about  115°  C.  sulphur  melts  and  would 
then  run  together  and  form  brimstone. 

Why  should  sulphur  be  protected  from  moisture? 
Moisture  aids  oxidation. 

Why  is  ammonia  used  in  making  washed  sulphur? 
It  neutralizes  any  free  acid,  making  it  easier  to  wash 
out,  and  it  dissolves  the  sulphide  of  arsenic  which  is 
frequently  present. 

Why  is  hydrochloric  acid  used  short  of  neutraliza- 
tion in  making  precipitated  sulphur?  Because  if 
an  excess  of  acid  is  used,  or  even  enough  to  cause 
neutrality,  the  soluble  compound  of  lime  and  sulphide 
of  arsenic  is  decomposed,  and  sulphide  of  arsenic  is 
precipitated  with  sulphur. 

Why  should  sulphuric  acid  not  be  substituted  for 
hydrochloric  acid  in  making  precipitated  sulphur? 
Sulphuric  acid  forms  the  nearly  insoluble  calcium 
sulphate,  which  could  not  be  removed. 

Why  is  precipitated  sulphur  whiter  than  the  flowers 
of  sulphur?     Because  it  is  more  finely  divided. 

Why  is  hydrochloric  acid  used  in  purifying  talcum? 
It  forms  soluble  compounds  with  many  of  the  impuri- 
ties, leaving  the  magnesium  silicate. 

Why   does   zinc   chloride   frequently    not   give   a 


116  WHYS   IN    PHARMACY. 

clear  solution  with  water?  On  account  of  a  basic 
chloride  which  can  best  be  gotten  rid  of  by  filtering 
through  asbestos  or  glass-wool. 

Why  is  it  necessary  to  treat  zinc  sulphate  with 
alcohol  in  order  to  determine  the  presence  or  absence 
of  free  acid?  The  salt  itself  is  acid,  but  it  is  not 
soluble  in  alcohol,  while  the  free  acid  is. 


ORGANIC  DRUGS. 

Why  is  a  powdered  drug  more  liable  to  deteriora- 
tion than  the  whole  drug?  Because  more  surface  is 
exposed  to  light  and  air. 

Why  should  ether  be  kept  away  from  light  and 
air?  It  is  slowly  oxidized,  forming  hydrogen  dioxide, 
ozone,  aldehyde,  and  acetic  and  formic  acids. 

Why  is  heat  produced  when  alcohol  and  water 
are  mixed?  Chemical  reaction  and  contraction  of 
volume  take  place,  forming  hydrates    of  alcohol. 

Why  is  alcohol  used  in  purifying  aloes?  The 
melted  aloes  is  too  thick  to  pass  through  the  sieve; 
alcohol  thins  it. 

Why  is  the  sieve  dipped  in  hot  water  just  before 
pouring  the  melted  aloes  through?  This  prevents 
the  clogging  of  the  sieve  by  the  chilled  mass. 

Why  should  aspidium  be  made  up  into  prepara- 
tions soon  after  collecting?  The  crude  drug  loses 
strength  more  rapidly  than  its  preparations  do. 
Filicic  acid  is  said  to  change  to  an  inactive  anhy- 
dride. 

Why  should  the  medicinal  parts  of  belladonna  be 

collected   from   the   second   to   fourth   years?    The 

117 


118  WHYS    IN  THARMACY. 

proportion  of  atropine  is  greater  during  that  period. 
In  the  young  plants  hyoscyamine  predominates. 

Why  should  the  large  woody  roots  of  belladonna 
be  rejected?    The  alkaloids  are  mostly  in  the  bark. 

Why  was  the  name  belladonna  applied  to  tliis 
drug?  The  word  signifies  beautiful  lady.  It  is  said 
that  Italian  ladies  used  this  drug  to  dilate  the  pupils 
of  the  eyes,  thus  giving  a  brilliant  appearance. 

Why  does  the  U.  S.  P.  give  the  title  ''caffeina 
citrata''  instead  of  caffeinae  citras?  This  prepara- 
tion is  probably  a  mixture  of  caffeine  and  citric 
acid  and  not  a  true  salt  as  would  be  indicated  by 
the  term  caffeinse  citras. 

Why  does  camphor  subhme  on  the  back  of  the 
stock-bottle?  The  back  of  the  bottle  is  nearer  the 
wall  which  is  generally  cooler  than  the  air  in  the 
store. 

Why  do  some  persons  claim  that  cannabis  indica 
should  be  kept  in  perforated  boxes?  They  say  that 
stored  in  this  way  it  retains  its  aromatic  properties 
for  two  or  three  years,  whereas  when  kept  in  tight 
containers  the  water  retained  by  the  drug  induces 
fermentation. 

Why  is  acid  used  in  purifying  animal  charcoal? 
It  dissolves  out  the  phosphates  and  carbonates.  In 
decolorizing  acid  liquids  only  the  purified  charcoal 
should  be  used. 

Why  is  animal  charcoal  used  for  decolorizing 
fluids  rather  than  wood  charcoal?  It  hao  a  stronger 
property  of  absorbing  colors. 


ORGANIC   DRUGS.  119 

Why  is  animal  charcoal  not  effective  as  a  decolor- 
izing agent  after  it  has  been  exposed  to  the  air  for 
some  time?  It  has  absorbed  gases  from  the  air 
which  prevent  the  absorption  of  coloring-matter. 
Heating  the  charcoal  will  again  make  it  effective. 

Why  is  starch  sometimes  found  in  beeswax  when 
it  is  not  put  there  as  an  adulterant?  In  pressing 
wax  into  cakes,  starch  is  put  on  to  the  rollers  to 
prevent  the  wax  from  sticking. 

Why  does  spermaceti  become  rancid  on  exposure 
to  air?  Rancidity  is  due  to  a  change  in  the  oil 
which  has  not  been  entirelv  removed. 

Why  does  the  U.  S.  P.  allow  as  much  as  one  per 
cent,  of  alcohol  to  be  present  in  chloroform?  This 
small  amount  of  alcohol  acts  as  a  preservative; 
chloroform  is  quite  easily  decomposed  when  pure. 

Why  is  chondrus  exposed  to  the  sun  for  a  week 
or  more?    To  bleach  it. 

Why  was  the  drug  cinchona  given  that  name? 
From  the  fact  that  the  wife  of  the  fourth  Count 
of  Chincon  was  cured  of  malaria  by  it,  and  she 
introduced  it  into  Europe. 

Why  are  some  specimeixS  of  coccus  cacti  black 
and  some  silver-gray?  The  silver-gray  bugs  are 
killed  by  the  heat  of  a  fire,  while  the  black  ones 
are  killed  by  hot  water. 

Why  are  the  cochineal  insects  called  coccus  cacti? 
They  get  the  name  coccus  from  their  resemblance  to 
a  berry  and  the  name  cacti  from  the  fact  that  they 
feed  on  a  species  of  cactus. 


120  WHYS   IN  PHARMACY. 

Why  should  the  pericarp  of  cardamom  be  dis- 
carded?   It  contains  but  Httle  oil. 

Why  is  creosote  usually  obtained  from  beechwood? 
Beechwood  yields  a  rather  larger  amount  than  other 
woods. 

Why  is  the  word  ''beechwood"  so  often  used  to 
describe  creosote?  An  impure  carbolic  acid  is  some- 
times sold  under  the  name  creosote. 

Why  are  cubebs  gathered  while  still  green?  They 
are  more  pungent  then  and  do  not  fall  off  so 
readily. 

Why  should  ergot  not  be  kept  longer  than  a  year? 
It  deteriorates  rapidly.  It  is  said  that  this  is  due 
to  the  fixed  oil  becoming  rancid,  and  that  if  the  oil 
is  removed  the  medicinal  properties  remain  unchanged 
for  a  long  time. 

Why  are  the  fluid  extract  and  the  extract  of 
ergot  the  best  preparations?  They  contain  all  the 
constituents  of  the  drug,  and  no  one  constituent 
represents  the  drug. 

Why  is  eucalpytus  cultivated  in  malarial  dis- 
tricts? The  tree  absorbs  much  water,  drying  up 
the  ground,  and  its  eminations  are  antagonistic  to 
the  malarial  germ. 

Why  is  gentian  used  more  than  other  bitters?  It 
has  a  pleasanter  taste  and  does  not  contain  tannin, 
so  can  be  given  with  iron. 

Why  is  alcohol  used  in  making  purified  ox-gall? 
Alcohol  precipitates  ine  t  matter  that  would  make 
the  gall  tough  when  dried  if  left  in. 


ORGANIC   DRUGS.  121 

Why  is  ginseng  valued  so  highly  by  the  Chinese? 
The  roots  often  grow  into  a  form  resembling  that 
of  a  man,  and  the  Chinese  have  a  superstition  that 
this  drug  will  cure  nearly  all  diseases. 

Why  is  glycerin  in  itself  not  a  good  solvent?  It 
is  so  viscid  that  it  prevents  diffusion. 

Why  is  glycerin  used  in  purified  honey?  To  aid 
preservation. 

Why  is  glycerin  used  in  making  gelatin  capsules? 
It  prevents  the  capsules  from  cracking  so  readily. 

Why  is  the  Spanish  glycyrrhiza  preferred  to  the 
Russian?    It  is  a  little  sweeter. 

Why  is  sulphuric  acid  used  in  making  ammoniated 
glycyrrhizin?  It  is  used  to  precipitate  glycyrrhizic 
acid,  which  can  be  filtered  out,  washed,  and  purified. 
Ammonia  water  added  later  converts  it  into  the 
soluble  salt. 

Why  is  purified  cotton  more  absorbent  than 
ordinary  cotton?  Ordinary  cotton  has  oil  and 
fatty  matter  in  it  which  prevent  the  absorption  of 
water.  In  purified  cotton  these  substances  have 
been  removed. 

Why  are  liquid  preparations  of  kino  unstable? 
The  pectin  present  often  causes  gelatinization. 

Why  is  lycopodium  called  vegetable  sulphur?  It 
is  yellow  like  sulphur  and  burns  readily. 

Why  are  nutmegs  limed?  To  protect  them  from 
insects. 

Why  is  sodium  hydroxide  used  in  obtaining  pure 
carbolic  acid  from  the  crude  product?    Crystalline 


122  WHYS    IN   THARMACY. 

sodium  phenolate  is  formed,  leaving  fluid  hydro- 
carbons and  other  impurities.  The  sodium  com- 
pound can  be  heated  to  170°  C.  without  decom- 
position, thus  getting  rid  of  other  substances. 

Why  was  phenol  called  an  acid?  Because  it 
combines  with  some  bases,  though  not  readily 
neutralizing  alkalies. 

Why  was  the  portion  of  the  distillate  coming 
over  between  165°  C.  and  190°  C.  called  '^dead  oil''? 
Because  it  was  thought  to  be  valueless. 

Wh}^  should  the  melting-point  of  carbolic  acid  be 
not  less  than  40°  C.  and  its  boihng-point  not  over 
188°  C?  A  lower  boiling-point  or  a  higher  melting- 
point  indicates  a  less  h3^drated  phenol. 

Why  should  care  be  used  in  melting  carbolic 
acid  ?  It  forms  an  inflammable  vapor,  and  when  this 
is  mixed  with  air  it  may  be  exploded  with  violence 
by  contact  with  a  flame. 

Why  does  carbolic  acid  acquire  a  red  color? 
Some  writers  say  it  is  due  to  the  presence  of  aurin 
and  rosolic  acid,  which  form  red  compounds  by 
absorption  of  carbon  dioxide  and  oxygen.  Other 
writers  say  it  is  due  to  absorption  of  ammonia 
and  ammonium  nitrate,  or  to  the  alkalies  in  the 
glass  of  the  container,  or  to  the  presence  of 
iron. 

Why  does  the  U.  S.  P.  give  the  solubihty  of  car- 
bolic acid  as  19.6  parts  of  water  when  the  acid  makes 
a  liquid  with  less  than  ten  per  cent,  of  water?  The 
addition  of  a  small  amount  of  water  converts  phenol 


ORGANIC    DRUGS.  123 

into  hydrates,  which  are  Hquid  but  not  very  soluble 
in  water. 

Why  is  an  excess  of  bromine  used  in  estimating 
carbolic  acid?  So  as  to  precipitate  all  of  the  acid 
as  tribromophenol. 

Why  is  potassium  iodide  used  in  estimating  car- 
boHc  acid?  The  excess  of  bromine  combines  with 
the  potassium,  liberating  an  equivalent  amount 
of  iodine,  which  is  more  easily  and  accurately 
estimated  by  sodium  thiosulphate  than  the  bro- 
mine. 

Why  are  the  preparations  of  pilocarpus  leaves  less 
reliable  than  preparations  of  pilocarpine?  The 
leaves  contain  jaborine  which  is  antagonistic  to 
pilocarpine  in  action.  The  proportion  of  the  two 
alkaloids  varies  in  different  samples  of  leaves. 

Why  is  physostigma  called  ordeal  bean?  In 
Africa  some  of  the  native  tribes  use  it  to  determine 
the  guilt  or  innocence  of  a  person  suspected  of  a 
crime.  The  accused  is  made  to  eat  the  beans 
until  he  vomits  or  dies.  If  he  vomits  and  lives  he 
is  innocent,  but  if  he  dies  he  is  guilty. 

Why  is  podophyllum  called  vegetable  mercury? 
Because  it  resembles  calomel  in  its  action. 

Why  must  the  mixture  of  acids  be  cooled  before 
putting  in  the  cotton,  in  making  pyroxyhn?  Because 
heat  causes  the  formation  of  higher  nitrates  of 
cellulose  which  are  less  soluble  in  alcohol  and  ether 
and  more  explosive. 

Why  should  the  bark  of  rhamnus  purshiana  be 


124  WHYS   IN   PHARMACY. 

one  or  more  years  old  before  using?  When  fresh  it 
contains  a  principle  that  causes  griping,  but  after 
standing  for  a  time  this  principle  disappears  and 
the  bark  no  longer  gripes. 

Why  should  red  rose  flowers  be  gathered  before 
complete  maturity  and  dried  rapidly?  Collecting 
early  makes  them  more  astringent,  and  drying 
rapidly  preserves  the  color  and  odor. 

Why  should  santonin  and  preparations  containing 
it  be  put  into  containers  which  protect  it  from  the 
light?     Light  causes  santonin  to  become  yellow. 

Why  is  santonin  better  than  the  sodium  santo- 
ninate  which  was  formerly  official?  Because  it  is  not 
so  soluble,  so  irritating,  or  so  readily  absorbed. 

Why  should  mustard  not  be  heated  over  60°  C. 
in  making  mustard  poultice?  A  heat  of  65°  C. 
makes  the  ferment,  myrosin,  inert  so  that  it  does 
not  convert  the  glucoside,  sinigrin,  into  the  volatile 
oil. 

Why  should  powdered  mustard  not  give  a  blue 
color  with  iodine?  A  blue  color  would  indicate 
the  presence  of  starch  as  an  adulterant;  mustard 
does  not  contain  starch  when  pure. 

Why  should  only  black  mustard  be  used  in  phar- 
macy? It  yields  the  volatile  oil  of  mustard  while 
the  white  mustard  does  not. 

Why  do  ribbons  of  tragacanth  have  longitudinal 
ridges  on  them?  Tragacanth  exudes  at  night 
through  incisions  made  in  the  bark.  The  exudation 
ceases  during  the  day  and  the  juice  dries,  and  th.3 


ORGANIC    DRUGS.  125 

ridge  indicates  the  amount  secreted  in  the  twenty- 
four  hours. 

Why  is  ginger  washed  in  boihng  water?  To 
prevent  it  from  germinating. 

Why  is  ginger  coated  with  hme?  To  protect  it 
from  insects. 


ALKALOIDS.     DRUG  ASSAYS. 

Why  was  the  term  '^alkaloid"  apphed  to  tho 
basic  principles  found  in  plants?  Alkaloid  means 
alkali-like — i.e.,  these  principles,  like  alkahes,  com- 
bine with  acids  to  form  salts. 

Why  is  the  definition,  '^An  alkaloid  is  an  organic 
base  found  in  the  plant  kingdom,  and  which  is  a 
pyridin  derivative,"  not  generally  acceptable? 
Because  this  shuts  out  at  least  two  principles  now 
classed  as  alkaloids,  viz.,  caffeine  and  theobromine. 

Why  does  the  prefix  ^^ hydro"  generally  enter 
into  the  name  of  an  alkaloidal  salt?  In  forming  a 
salt  of  an  alkaloid,  the  hydrogen  of  the  acid  is  not 
displaced;  the  whole  acid  is  added  on,  and  the 
prefix  shows  this. 

Why  should  alkaloids  be  protected  from  the  hght? 
Light  often  decomposes  alkaloids,  slowly  causing 
a  darkening. 

Why  is  less  dependence  now  placed  on  chemical 
tests  for  alkaloids  than  formerly?  We  now  know 
that  many  synthetic  bases  and  ptomaines  give 
reactions  similar  to,  if  not  identical  with,  those 
given  by  alkaloids. 

126 


ALKALOIDS.  127 

Why  is  the  complete  separation  and  estimation 
of  alkaloids  so  difficult?  Alkaloids  frequently  do 
not  form  compounds  with  any  known  reagent  that 
are  sufficiently  insoluble  to  permit  of  separation. 

Why  is  the  general  method  of  estimating  alkaloids 
by  weighing  the  free  alkaloid  objectionable?  If  the 
alkaloid  is  first  precipitated,  the  mother  liquid  will 
hold  more  or  less  of  it  in  solution,  and  the  alkaloid 
will  rarely  come  down  pure.  If  the  alkaloid  is 
removed  by  dissolving  it  in  some  immiscible  solvent, 
it  will  be  mixed  with  some  foreign  matter. 

Why  is  the  general  method  of  estimating  alkaloids 
by  precipitation  with  Mayer's  reagent,  and  then 
weighing  the  precipitate,  objectionable?  The  com- 
pound formed  between  the  alkaloid  and  the  reagent 
may  vary  under  different  conditions  of  precipitation. 
Drying  this  compound  may  change  its  composi- 
tion. Mayer's  reagent  precipitates  many  other  sub- 
stances. 

Why  is  the  method  of  estimating  alkaloids  by  a 
standard  solution  of  Mayer's  reagent  objectionable? 
It  is  very  difficult  to  tell  when  the  end  reaction  is 
obtained,  and  the  amount  required  varies  with  the 
concentration  of  the  alkaloidal  solution,  as  well  as 
with  other  conditions. 

Why  is  the  method  of  estimating  alkaloids  by 
standard  acid  and  alkali  solutions  objectionable? 
Many  times- it  is  difficult  to  detect  the  end  reaction, 
and  various  indicators  act  differently  with  alkaloids. 
By  precipitating  the  alkaloid  from  an  acid  solution 


128  WHYS    IN    THARMACY. 

by  iodine,  filtering,   and  titrating  the  filtrate  the 
end  reaction  is  more   distinct. 

Why,  in  extracting  alkaloids  for  assaying,  are 
acidulated  water  and  alkaline  immiscible  solvents 
alternately  used?  The  separation  of  alkaloids  by 
this  method  depends  upon  the  facts  that  free  alka- 
loids are  generally  soluble  in  immiscible  solvents  and 
insoluble  in  water,  and  the  alkaloidal  salts  are  soluble 
in  water  and  insoluble  in   the   immiscible  solvents. 

Why  should  such  alkaloids  as  atropine,  aconitine, 
hyoscyamine,  and  cocaine  not  be  left  in  an  alkaline 
solution  any  longer  than  is  necessary  in  separating 
them  from  the  crude  drugs?  They  are  all  easily 
decomposed  by  simple  contact  with  an  alkali  for  a 
short  time. 

Why  should  cinchona  be  in  very  fine  powder  for 
assay  purposes?    The  bark  is  hard  to  exhaust. 

Why  is  a  mixture  of  ether,  chloroform,  and  am- 
monia used  to  extract  the  alkaloids  in  assaying  the 
bark?  Ammonia  liberates  the  alkaloids,  which  are 
then  dissolved  in  chloroform  and  ether. 

Why  should  care  be  taken  to  measure  accurately 
and  to  allow  no  evaporation  of  this  liquid?  150  cc. 
are  used  to  extract  the  drug,  and  100  cc.  of  this  are 
taken  to  represent  two  thirds  of  the  drug  taken.  If 
evaporation  is  allowed,  100  cc.  will  represent  more 
than  10  grams. 

AVhy  are  the  100  cc.  treated  with  dilute  sulphuric 
acid?  Acid  converts  the  alkaloids  into  sulphates 
which  are  soluble. 


ALKALOIDS.  129 

Why  is  the  acid  fluid  shaken  with  ammonia, 
ether,  and  chloroform  in  estimating  anhydrous 
alkaloids?  Ammonia  liberates  the  alkaloids;  and 
the  ether  and  chloroform  dissolve  them. 

Why  ''add  3  cc.  of  ether  to  the  dry  residue  and 
evaporate  again''?  To  aid  the  complete  removal  of 
moisture. 

Why  is  quinine  (free  alkaloid)  mixed  with  am- 
monium sulphate  and  water,  and  then  dried,  in  the 
official  method  of  testing  quinine  for  other  cinchona 
alkaloids?  In  order  to  convert  all  the  alkaloids 
into  sulphates,  ammonia  being  volatilized. 

Why  are  the  alkaloids  converted  into  sulphates? 
Because  quinine  sulphate  is  more  insoluble  in  water 
than  the  other  sulphates,  and  treating  this  mixture 
with  water  dissolves  most  of  the  sulphates  of  alka- 
loids other  than  quinine  and  comparatively  little  of 
the  quinine  sulphate. 

Why  is  the  mixture  of  cinchona  alkaliods  digested 
with  water  at  65°  C.  then  kept  at  a  temperature 
of  15°  C.  for  two  hours  and  filtered  at  that  tem- 
perature? When  quinine  sulphate  is  crystalHzed 
from  a  liquid  containing  other  alkaloids  the  crystals 
seem  to  take  in  some  of  the  other  alkaloids  (they 
are  inside  the  crystals,  not  merely  on  the  outside). 
The  elevated  temperature  is  for  the  purpose  of 
dissolving  more  of  the  quinine.  The  mixture  is 
cooled  to  15°  C.  and  filtered  at  that  temperature 
in  order  to  get  uniform  results  and  prevent  too 
much   quinine   sulphate   from   going  into   solution; 


130  WHYS    IN    PHARMACY. 

excess  of  quinine  is  not  dissolved  by  ammonia. 
The  mixture  is  kept  at  15°  C.  for  two  hours  before 
filtering  so  as  to  allow  complete  crystallization, 
getting  only  a  saturated  filtrate. 

Why  is  ammonia  added  to  the  filtrate?  By  add- 
ing the  stated  amount  of  ammonia  to  the  given 
amount  of  filtrate,  enough  ammonia  is  added  to 
Hberate  all  of  the  alkaloids  and  to  redissolve  the 
quinine  which  is  present,  but  not  the  other  alkaloids. 
The  test  is  based  on  two  principles:  (1)  the  com- 
parative solubility  of  the  sulphates  of  alkaloids 
other  than  quinine  in  water,  and  (2)  the  comparative 
insolubihty  of  these  alkaloids  in  ammonia  when  in 
the  free  state. 

Why  are  the  other  salts  of  quinine  converted  into 
the  sulphate  in  applying  this  test?  To  get  uniform 
results  and  to  fulfil  the  condition  as  laid  down  in 
the  first  principle. 

Why  is  quinine  tannate  nearly  tasteless?  Because 
it  is  so  nearly  insoluble. 

^YhJ  is  nitric  acid  used  in  estimating  strychnine 
in  nux  vomica  and  its  preparations?  Nitric  acid 
decomposes  brucine  which  is  extracted  with  the 
strychnine  and  changes  it  so  that  chloroform  no 
longer   dissolves   it   from   an   alkaline   solution. 

Why  is  the  filter  wetted  with  chloroform  just 
before  filtering  the  chloroform  extract  of  the  mix- 
ture after  treating  with  nitric  acid?  So  that  the 
filter  will  not  retain  any  strychnine  and  to  prevent 
any  aqueous  solution  from  getting  into  the  flask. 


ALKALOIDS.  131 

Why  is  it  particularly  objectionable  to  have  any 
of  the  aqueous  liquid  get  into  the  flask  at  this  stage 
of  the  process?  The  aqueous  liquid  contains  free 
alkali  which  would  neutralize  some  of  the  standard 
acid,  acting  like  strychnine. 

Why  is  fiftieth-normal  potassium  hydroxide  used 
to  titrate  back  the  excess  of  decinormal  acid? 
Rather  more  accurate  results  can  be  obtained  than 
when  decinormal  alkali  is  used. 

Why  divide  the  number  of  cubic  centimeters  of 
fiftieth-normal  potassium  hydroxide  by  5?  So  as  to 
reduce  the  fiftieth-normal  to  its  equivalent  in  deci- 
normal. 

Why  subtract  this  quotient  from  10?  10  cc.  of 
decinormal  acid  were  used  at  first.  Subtracting  the 
above  quotient  from  10,  the  remainder  is  the  number 
of  cubic  centimeters  of  acid  which  were  taken  up  or 
neutralized  by  the  alkaloids. 

Why  multiply  the  remainder  by  0.0332?  Each 
cubic  centimeter  of  decinormal  acid  neutralizes 
0.0332  gram  of  strychnine. 

Why  is  this  product  multiplied  by  50?  The  assay 
method  gets  the  alkaloid  in  2  grams  of  extract,  and 
by  multiplying  by  50  gives  the  weight  in  100  grams. 

Why  is  it  difficult  to  tell  when  the  acid  is  exactly 
neutralized  by  the  alkali?  The  hquid  which  is  to 
be  titrated  is  often  colored.  It  is  better  to  add 
neutral  Mayer's  reagent,  or  a  solution  of  iodine, 
to  the  acid  solution,  filter,  and  then  titrate  the  filtrate 
with  the  alkali. 


132  WHYS    IN    PHARMACY. 

Why  is  manganese  dioxide  preferred  by  some 
workers  to  j3otassium  dichromate,  in  testing  for 
strychnine?  Potassium  dichromate  itself  gives  a 
color  that  may  hide  the  strychnine  color  if  strych- 
nine is  present  in  only  small  amounts. 

Why  is  powdered  opium  better  for  making  prepa- 
rations than  the  gum?  It  is  more  uniform  and 
does  not  change  so  much  on  keeping. 

Why  is  it  that  water  will  exhaust  opium  when  it 
will  exhaust  almost  no  other  alkaloidal  drug?  The 
alkaloids  of  opium  exist  in  the  form  of  meconates 
and  sulphates,  which  are  soluble,  while  in  most 
other  drugs  the  alkaloids  are  in  combination  with 
tannic  acid,  which  salts  are  nearly  insoluble. 

Why,  in  assaying  gum  opium,  should  a  cone- 
shaped  piece  be  taken  with  the  apex  of  the  cone 
at  the  center  of  the  lump?  The  outside  of  the 
lump  is  always  dryer  than  the  center,  and  by  taking 
a  cone  a  proportional  amount  of  the  dry  and  the 
moist  opium  is  obtained. 

Why,  in  the  official  method  of  estimating  opium, 
is  an  Erlenmeyer  flask  directed  to  be  used?  The 
crystals  can  be  removed  more  easily.  The  writer 
prefers  a  Florence  or  globe-shaped  flask,  because  there 
is  less  area  of  surface  when  decanting  the  ether,  and 
consequently  the  ether  can  be  more  closely  separated. 

Why  are  alcohol,  ether,  and  ammonia  added  to 
the  concentrated  extract  of  opium  in  assaying  it? 
The  alcohol  prevents  the  precipitation  of  a  con- 
siderable  amount   of   foreign   matter   by   ammonia. 


ALKALOIDS.  133 

Ether  keeps  in  solution  the  alkaloids  other  than 
morphine,  they  being  soluble  in  ether  while  mor- 
phine is  not.  Ammonia  liberates  the  alkaloids  from 
their  salts  and  morphine  is  precipitated.  The  aqueous 
extract  is  concentrated  so  that  as  little  morphine  will 
be  left  in  the  mother-liquor  as  possible. 

Why  does  the  U.  S.  P.  direct  to  shake  this  mix- 
ture for  ten  minutes?  Agitation  aids  precipitation, 
making  the  morphine  come  down  more  promptly 
and  completely.  Even  then  the  mixture  must  stand 
six  hours  or  more. 

Wiry  should  the  mixture  not  stand  longer  than 
about  twenty-four  hours?  After  that  time  other 
matter  than  morphine  precipitates. 

Why  does  the  U.  S.  P.  direct  two  rapidly  acting 
filters?  Two  filter-papers  are  used  to  quicken  fil- 
tration. The  writer  much  prefers  a  single  filter  of 
hardened  paper  from  which  the  crystals  can  be 
readily  removed  without  leaving  any  on  the  paper, 
or  getting  fibers  of  paper  mixed  with  the  crystals. 

Why  are  the  contents  of  the  flask  washed  twice 
with  ether?  So  as  to  remove  other  alkaloids  as 
far  as  possible. 

Why  are  the  crystals  washed  with  alcohol  satu- 
rated with  morphine?  They  are  washed  with  alco- 
hol to  remove  coloring  and  other  foreign  matter. 
The  alcohol  is  saturated  with  morphine  so  that 
it  will  not  dissolve  any  of  the  crystals. 

Why  is  the  alcohol  saturated  with  morphine 
washed  out  with  ether?     If   the  alcohol  were  not 


134  WHYS    IN    PHARMACY. 

washed  out  it  would  evaporate,  leaving  the  mor- 
phine originally  dissolved  in  it,  making  the  results 
too  high. 

Why  are  the  crystals  dried  at  a  temperature  not 
exceeding  60°  C?  If  the  crystals  were  dried  at 
100°  C.  part  but  not  all  of  the  water  of  crystalhza- 
tion  would  be  driven  off,  the  amount  varying.  A 
higher  temperature  is  necessary  to  drive  off  all 
the  water,  and  there  is  some  danger  of  the  decom- 
position of  morpliine.  Morphine  crystallizes  and  is 
weighed  with  one  molecule  of  water. 

Why  are  the  crystals  transferred  to  a  watch-glass 
for  weighing?  They  cannot  be  weighed  accurately 
on  filter-paper,  since  filter-paper  absorbs  moisture 
during  weighing.  Then,  too,  filter-paper  loses  some 
weight  on  being  subjected  to  various  solvents. 

Why  is  lime  water  used  in  assaying  opium?  It 
is  used  to  dissolve  morphine,  leaving  some  impurities 
undissolved,  which  are  filtered  out. 

Why  is  the  use  of  lime  water  objectionable? 
The  filter-papers,  though  counterpoised  at  first,  do 
not  necessarily  retain  the  same  amount  of  calcium 
hydroxide;  then  more  qr  less  of  the  hydroxide  is 
converted  into  the  carbonate.  This  variation  in 
amount  of  lime  in  the  two  papers  is  liable  to  cause 
serious  error.  Moreover,  experiments  made  by 
the  writer  indicate  that  though  two  filter-papers 
are  treated  by  the  same  liquid  they  do  not  always 
change  the  same. 

Why,    in    estimating    morphine    in    tincture    of 


ALKALOIDS.  135 

opium,    is    the    tincture    evaporated?    To    get    rid 
of  the  alcohol,   and  to  concentrate  the  hquid. 

Why,  in  estimating  morphine  in  laudanum,  is 
water  added  to  the  concentrated  tincture?  To 
precipitate  resinous  matter. 

Why,  in  estimating  morphine  in  laudanum,  does 
a  precipitate  sometimes  form  on  evaporating  the 
filtrate  to  the  14  grams?  The  precipitate  is 
probably  narcotine.  Narcotine  exists  in  opium 
loosely  combined  with  an  acid,  and  the  heat  during 
evaporation  decomposes  the  salt,  liberating  nar- 
cotine which  is  insoluble  in  water. 

Why  is  morphine  more  bitter  when  combined  with 
a  common  acid  than  when  free?    It  is  more  soluble. 

Why  does  morphine  acetate  become  less  soluble  with 
age?    It  loses  acetic  acid,  leaving  the  free  alkaloid. 

Why  should  the  solution  of  ferric  chloride  used 
in  testing  morphine  be  nearly  neutral?  Any  excess 
of  acid  destroys  or  prevents  the  coloration. 

Why  does  Froehde's  reagent  (ammonium  molyb- 
date  in  sulphuric  acid)  give  a  blue  color  with  mor- 
phine? Morphine  reduces  molybdic  acid  to  lower 
oxides  of  the  metal. 

Why  does  iodic  acid  with  starch  and  morphine 
give  a  blue  color?  Morphine  reduces  iodic  acid, 
liberating  iodine  which  gives  a  blue  compound  with 
starch. 

Why  was  the  alkaloid  narcotine  given  that  name? 
It  was  thought  at  first  to  be  the  narcotic  principle 
of  opium. 


136  WHYS    IN    PHARMACY. 

Why  is  the  finding  of  meconic  acid  of  any  impor- 
tance in  a  case  of  toxicology?  It  indicates  that 
opium  and  not  pure  morphine  was  taken. 

Why  is  the  gravimetric  method  of  assaying  aconite 
objectionable?  Aconite  contains  several  alkaloids 
that  can  be  put  into  two  classes,  the  aconitine 
alkaloids  and  the  aconine  alkaloids,  the  former 
being  active  and  the  latter  nearly  inert.  The  aconi- 
tine alkaloids  are  converted  to  some  extent  into 
the  aconine  compounds  in  drying  the  drug,  and 
by  heat  and  alkahes  during  the  process  of  assay; 
and  though  a  large  amount  of  alkaloids  are  obtained 
a  variable  proportion  of  them  is  inert. 

Wliy  should  the  use  of  aconitine  be  discouraged? 
The  commercial  article  is  extremely  variable,  and 
absolute  aconitine  is  one  of  the  most  active  of  drugs. 

Why  does  the  U.  S.  P.  direct  that  the  containers 
for  apomorphine  hydrochloride  be  previously  rinsed 
with  hydrochloric  acid?  Glass  bottles  are  fre- 
quently sufficiently  alkahne  to  render  the  contents 
somewhat  alkaline,  and  this  tends  to  decomiDose 
the  apomorphine. 

Why  is  no  acid  used  in  assaying  colchicum? 
The  alkaloid  is  easily  decomposed  by  acids,  often 
forming  colored  compounds.  The  acid  is  not  neces- 
sary as  the  alkaloid  is  soluble  in  about  22  parts  of 
water. 

Why  is  acid  added  to  the  ethereal  solution  before 
evaporating  in  assaying  conium?  To  pi-event  the 
vaporization  of  coniine,  which  is  a  volatile  alkaloid. 


ALKALOIDS.  137 

Why  is  hydras  tine  called  "  white  alkaloid"?  In 
order  to  distinguish  it  from  berberine,  the  "  yellow 
alkaloid  ''.  Berberine  was  separated  before  hydras- 
tine,  and  it  was  first  called  hydrastine. 

Why  is  pilocarpine  preferable  to  pilocarpus?  It 
is  more  uniform  in  strength.  Pilocarpus  contains 
another  alkaloid,  jaborine,  which  is  antagonistic  to 
pilocarpine. 

Why  does  physostigma  vary  so  much  in  activity? 
It  contains  two  alkaloids,  physostigmine  and  cala- 
barine,  which  vary  in  proportion  and  are  antago- 
nistic to  each  other. 

Why  is  sodium  bicarbonate  used  instead  of  ammo- 
nia in  assaying  physostigma?  The  bicarbonate  is 
less  alkaline  and  physostigmine  is  easily  decomposed 
by  alkalies,  forming  colored  compounds. 

Why  is  ether  added  to  the  solution  just  before 
titrating  back  the  excess  of  acid  in  assaying  physo- 
stigma? The  indicator,  iodeosin,  acts  better  in  the 
presence  of  ether. 

Why  is  a  trace  of  hypophosphorous  acid  some- 
times added  to  a  solution  of  physostigmine  salicylate? 
Unless  protected  the  solution  soon  becomes  red- 
blue,  due  to  the  formation  of  rubeserin.  One  part 
of  dilute  hypophosphorous  acid  to  five  hundred  of 
solution  is  said  to  be  sufficient  to  keep  it. 

Why  should  the  use  of  official  veratrine  be  dis- 
couraged? It  is  a  mixture  of  alkaloids  and  varies 
in  proportion  to  its  different  ingrejdients. 


PRESCRIPTIONS. 

Why  should  prescriptions  be  written  in  Latin? 
(1)  It  is  a  language  understood  throughout  the 
world.  (2)  It  is  a  dead  language,  and  therefore  is 
not  changing.  (3)  Common  names  vary  in  different 
parts  of  the  country,  while  Latin  ones  are  distinctive. 
(4)  Technical  Latin  is  not  usually  understood  by 
the  patient,  and  so  there  is  not  the  danger  of  arousing 
prejudice.  (5)  The  tendency  to  self-medication  is 
not  increased. 

Why  should  the  physician  sign  his  full  name  to 
a  prescription  and  not  simply  his  initials?  It  some- 
times happens  that  the  prescriber  has  made  a  mis- 
take, or  for  other  reasons  the  compounder  wants  to 
communicate  with  the  writer,  and  in  a  large  town 
the  prescription  may  be  carried  to  a  part  where  the 
prescriber  is  not  known. 

Why  is  "J^^'  placed  at  the  head  of  prescription 
blanks?  It  stands  for  the  verb  "  recipe,''  meaning 
to  take.  Originally  the  sign  of  Jupiter,  n,  was 
used   as  a  prayer  asking  for  healing. 

Why  do  many  pharmacists  write  the  label  before 

138 


PRESCRIPTIONS.  139 

filling  the  prescription?  The  label  has  time  to 
become  thoroughly  dry,  and  they  have  time  to  con- 
sider  the   best   way   of   filling  it. 

Why  should  the  pharmacist  notice  carefully  the 
doses  of  all  strong  medicines  when  they  are  pre- 
scribed? The  physician  is  human  and  liable  to 
make  an  error.  In  law  the  pharmacist  as  well  as 
the  physician  is  held  responsible  in  case  injury 
results  from  an  overdose,  and  suit  for  damages  is 
more  likely  to  be  brought  against  the  pharmacist 
than  the  physician. 

Why  should  the  directions,  "  Use  as  directed,"  be 
avoided  by  the  prescriber?  The  patient  is  gen- 
erally in  a  more  or  less  nervous  condition  and  likely 
to  forget  the  details.  Then,  too,  by  having  the 
directions  on  the  prescription  it  makes  another 
safeguard  in  that  the  pharmacist  can  more  readily 
detect  an  error  if  present.  Upon  the  dose  depends 
the  safety. 

Why  is  there  a  direct  loss  in  buying  such  chemi- 
cals as  morphine  and  strychnine  in  one  eighth 
ounce  bottles  and  selling  it  by  the  grain  unless 
the  price  is  advanced  more  than  enough  to  cover 
the  apparent  cost  of  selling?  The  substance  is 
bought  by  avoirdupois  weight,  which  has  only 
54.7  grains  in  one  eighth  of  an  ounce,  while  it  is 
sold  by  apothecary  weight,  which  has  60  grains  in 
an  eighth  of  an  ounce. 

Why  is  there  a  loss  in  buying  quinine  sulphate 
in  bulk  and  retaiUng  it  in  small  amounts?    Tliis 


140  WHYS    IN    PHARMACY. 

salt  loses  a  considerable  amount  of  water  of  crystal- 
lization, and  more  quinine  is  sold  for  a  given  weight 
than  is  bought. 

Why  should  heat  not  be  generally  used  in  making 
solutions  at  the  prescription  counter?  Heat  may 
volatilize  or  decompose  some  ingredient  or  make  a 
supersaturated  solution  that  will  deposit  large  crys- 
tals on  cooling. 

Why  is  it  usually  preferable,  in  mixing  an  insoluble 
substance  with  a  liquid,  to  rub  it  in  the  mortar  with 
a  small  amount  of  liquid  first?  If  the  solid  is  simply 
put  into  a  bottle  and  shaken  the  substance  may 
''lump"  and  require  time  and  agitation  in  order  to 
get  it  mixed.  This  is  particularly  true  with  calomel, 
magnesia,  sulphur,  or  a  vegetable  drug. 

Why  is  it  frequently  preferable,  in  mixing  solu- 
tions that  will  precipitate,  to  have  the  solutions  cold 
and  as  dilute  as  possible  before  mixing  them?  The 
precipitate  will  be  finer,  lighter,  and  more  easily  dif- 
fused through  the  liquid. 

Why  should  heat  not  be  used  in  making  solutions 
of  alkali  bi carbonates?  Heat  decomposes  them, 
liberating  carbon  dioxide  and  leaving  the  normal 
carbonate. 

Why  should  ammonium  carbonate  be  dissolved  in 
the  cold?  Heat  volatilizes  ammonia  and  carbon 
dioxide. 

Why  is  it  generally  best,  when  necessary  to  mix 
them,  to  add  an  alcoholic  solution  of  a  substance  in- 
soluble in  water,  to  the  water,  rather  than  the  water 


PRESCRIPTIONS.  141 

to  the  alcohol?  The  substance  is  precipitated  in  a  finer 
form  and  is  more  easily  diffused.  However,  in  some 
cases  where  there  is  a  comparatively  large  amount  of 
alcohol,  and  a  small  amount  of  precipitation,  it  is 
better  to  add  the  water  to  the  alcoholic  solution. 

Why  should  a  stock  solution  of  mercuric  chloride 
contain  a  little  ammonium  chloride?  Ammonium 
chloride  prevents  the  reduction  that  slowly  takes 
place  in  a  solution  of  pure  mercuric  chloride. 

Why  does  ammonium  chloride  make  mercuric  chlo- 
ride more  soluble?  Probably  because  a  more  soluble 
double  compound  is  formed. 

Why  is  citric  or  tartaric  acid  sometimes  added  to 
mercuric  chloride  tablets?  To  render  the  solution 
made  from  them  more  penetrating,  by  preventing  the 
formation  of  an  insoluble  compound  with  albumin. 

Why  should  potassium  iodide  not  be  kept  long  in 
stock  solution?  Iodine  is  liberated.  This  can  be 
prevented  to  some  extent  by  the  presence  of  an  alkali 
carbonate,  but  this  is  often  objectionable. 

Why  should  bicarbonates  of  alkalies  not  be  kept 
in  stock  solutions?  They  lose  carbon  dioxide  and 
become  more  alkaline. 

Why  should  chloral  hydrate  not  be  kept  in  stock 
solution?    It  decomposes,  becoming  acid. 

Why  cannot  hypodermic  solutions  be  rendered 
aseptic  by  heat?  Those  medicinal  substances  which 
are  usually  administered  hypodermically  are  more  or 
less  decomposed  by  heat. 

Why  cannot  alcohol  be  used  as  a  preservative  for 


142  WHYS   IN   THARMACY. 

hypodermic  solutions?  Comparatively  large  amounts 
of  alcohol  would  be  necessary  to  accomplish  the  pur- 
pose, and  alcohol,  when  injected,  is  an  irritant  and 
astringent. 

Why  should  mucilage  of  acacia  not  be  used  to  sus- 
pend insoluble  substances  in  lotions?  It  leaves  the 
skin  sticky  or  hard.  Tragacanth  is  less  objectionable, 
as  a  much  smaller  amount  will  serve  the  same  pur- 
pose. 

Why  are  acacia  and  tragacanth  objectionable  in 
suspending  bismuth  subnitrate  in  a  liquid?  Traga- 
canth seems  to  combine  with  the  bismuth  salt,  form- 
ing a  curdy  precipitate.  When  acacia  is  used  and 
the  bismuth  settles,  it  is  difficult  and  sometimes  im- 
possible to  shake  up.  Scoville  suggests  the  use  of 
tragacanth  with  the  addition  of  a  little  alcohol. 

Why  should  eye-washes  and  hypodermic  solutions 
be  filtered?  To  be  sure  that  no  solid  matter  is  left 
that  would  cause  irritation. 

Why  cannot  as  much  of  certain  powdered  salts, 
such  as  alum  or  Rochelle  salt,  be  dissolved  in  water 
as  is  the  case  with  crystals?  In  the  powdered  con- 
dition the  salt  has  lost  some  of  its  water  of  crystalliza- 
tion, and  there  is  consequently  more  of  the  salt  proper 
in  a  given  weight  than  is  the  case  with  the  crystals. 

Why  should  such  substances  as  calomel  and  ipecac 
be  very  finely  divided?  The  finer  the  powders  the 
more  active  they  seem  to  be. 

Why  should  the  following  substances  not  be  dis- 
pensed in  the  form  of  a  powder:   Carbolic  acid,  cal- 


PRESCRIPTIONS.  143 

cium  bromide,  iron  and  ammonium  citrate,  potas- 
sium acetate,  potassium  carbonate,  potassium  hypo- 
phosphite,  sodium  hypophosphite,  potassium  iodide 
sodium  iodide,  strontium  bromide,  granular  efferves- 
cing salts,  and  sodium  bromide?  They  are  hygro- 
scopic or  deliquescent. 

Why  should  the  following  substances  not  be  dis- 
pensed in  the  form  of  powders:  Ferrous  sulphate, 
lead  acetate,  sodium  carbonate,  sodium  sulphate, 
sodium  phosphate,  and  zinc  acetate?  They  lose 
water  of  crystallization  and  become  more  concen- 
trated. 

Why  should  the  following  substances  not  be  dis- 
pensed in  the  form  of  powders :  Ammonium  carbonate, 
chloral,  lead  acetate,  camphor,  the  iodides  of  mer- 
cury, and  the  salts  of  silver?  Ammonium  carbonate 
loses  ammonia  and  carbon  dioxide;  chloral  is  irri- 
tating; lead  acetate  loses  acetic  acid  and  becomes 
insoluble;  the  iodides  of  mercury  darken;  camphor 
volatilizes;   and  the  silver  salts  are  reduced. 

Why  should  the  following  substances  not  be  pre- 
scribed together  in  the  form  of  powders:  Antipyrine 
with  carbolic  acid,  resorcin,  or  thymol;  camphor  with 
carbolic  acid,  chloral  hydrate,  menthol,  naphtol,  re- 
sorcin, salol,  or  thymol;  chloral  with  euphorin,  exal- 
gin,  phenacetin,  menthol,  salol,  or  thymol?  They 
liquefy  or  form  soft  masses. 

Why  is  it  that  a  good  many  crystalline  compounds 
liquefy  when  rubbed  together?  Heat  of  trituration 
may  be  sufficient  to  start  chemical  reaction,  forming 


144  WHYS   IN   PHARMACY. 

liquid  compounds  in  some  cases,  and  water  of  crys- 
tallization may  be  liberated  in  other  cases. 

Why  should  chlorates,  permanganates,  silver  oxide 
chromates,  or  nitrates  not  be  rubbed  with  organic 
matter    or    other    reducing   matter?     Because    the 
liberation  of  a  large  amount  of  gas  will  cause  an 
explosion. 

Why  should  solutions  containing  potent  substances 
like  strychnine  be  filtered  before  dispensing?  To  be 
certain  that  none  is  left  undissolved,  avoiding  danger 
of  an  overdose  at  the  last  of  the  prescription. 

Why  is  the  presence  of  alcohol  often  advisable  when 
an  alkaloid  salt  is  prescribed  with  other  compounds? 
A  large  number  of  compounds  precipitate  alkaloids; 
alcohol  frequently  prevents  this  precipitation. 

Why  should  a  mixture  of  mercuric  chloride  and  po- 
tassium iodide  not  be  given  with  an  aqueous  solution 
of  an  alkaloidal  salt?  Mercuric  chloride  and  potassium 
iodide  cause  the  formation  first  of  mercuric  iodide  and 
potassium  chloride.  Then  the  mercuric  iodide  com- 
bines with  more  potassium  iodide,  forming  Mayer's 
reagent  (potassium  mercuric  iodide),  which  precipi- 
tates alkaloids.  Even  when  the  precipitated  alkaloid 
is  harmless,  the  mixture  may  be  dangerous  on  account 
of  the  mercuric  compound  which  is  precipitated. 

Why  is  more  carbon  dioxide  given  off  when  a  car- 
bonate is  mixed  with  a  solution  of  a  salt  of  tin,  anti- 
mony, ferric  iron  and  aluminium  than  when  mixed 
with  salts  of  other  metals  (not  considering  the  pres- 
ence of  a  free  acid)?    The  carbonate  forms  hydrox- 


PRESCRIPTIONS.  145 

ides  or  oxides  with  these  metalhc  salts,  practically  all 
of  the  carbon  dioxide  being  ehminated.  With  the 
other  metallic  salts  it  forms  a  normal  or  basic  car- 
bonate. 

Why  is  honey  a  good  addition  to  mixtures  calling 
for  tincture  of  myrrh  and  aqueous  solutions?  Water 
usually  precipitates  resin  of  myrrh  in  a  form  that 
soon  sticks  together  and  adheres  to  the  sides  of  the 
bottle.  Honey  does  not  prevent  precipitation,  but 
holds  the  resin  in  a  flocculent  condition,  so  that  it  is 
easily  suspended. 

Why  is  a  mixture  of  lead  water  and  laudanum  a 
poor  combination  pharmaceutically  ?  Lead  subace- 
tate  combines  with  sulphuric  acid,  meconic  acid,  and 
the  alkaloids  in  opium,  forming  insoluble  compounds 
with  all  of  them. 

Why  does  effervescence  take  place  when  ammo- 
nium carbonate  is  added  to  syrup  of  garlic,  ipecac, 
or  squill?  These  syrups  contain  free  acetic  acid, 
which  reacts  with  the  carbonate. 

Why  does  the  variation  in  the  order  of  mixing 
potassium  chlorate,  hydrochloric  acid,  and  water 
cause  a  variation  in  color?  Adding  hydrochloric 
acid  to  the  chlorate  and  then  adding  water  gives  a 
yellow-green  solution,  due  to  the  chlorine  formed. 
Adding  water  to  the  chlorate  or  to  hydrochloric 
acid,  and  then  adding  the  remaining  ingredient, 
gives  a  colorless  solution.  There  is  not  nearly  as 
much  chlorine  formed  by  this  as  by  the  first  method. 

Why  should  glycerin  be  added  to  a  mixture  of 


146  WHYS    IN    PHARMACY. 

carbolic  acid  and  water  when  the  proportion  of 
acid  to  water  is  much  greater  than  1  to  15?  Car- 
bohc  acid  separates  from  the  mixture  when  the  pro- 
portion is  much  above  this,  and  the  glycerin  pre- 
vents separation. 

Why  should  care  be  used  in  prescribing  antipy- 
rine  in  combination  with  other  compounds?  Anti- 
pyrine  resembles  alkaloids  in  its  precipitations,  being 
thrown  out  of  solution  by  about  the  same  substances 
that  precipitate  alkaloids. 

Why  does  a  mixture  of  fluid  extract  of  gelsemium, 
chloral  hydrate,  antipyrine,  and  water  separate 
into  layers?  Antipyrine  and  chloral  hydrate  form 
one  or  more  chloral-antipyrines  which  are  liquid 
at  first  but  may  become  solid.  One  of  these  com- 
pounds is  hypnal.  Antipyrine  liquefies  with  quite 
a  large  number  of  compounds. 

Why  should  gold  and  sodium  chloride  not  be 
put  into  the  same  prescription  with  potassium 
iodide?  Decomposition  takes  place,  with  the  for- 
mation of  different  compounds,  depending  on  the 
excess  of  the  one  or  the  other  salt.  Potassium  iodide 
is  usually  in  excess  and  auric  iodide  is  formed,  chang- 
ing to  aurous  iodide. 

Why  should  ichthyol  not  be  given  with  anything 
that  is  acid?  Acids  combine  with  ammonia  in 
ichthyol  and  precipitate  ichthyosulphonic  acid  as  a 
dark,  resinous,  adhesive  mass. 

Why  is  spirit  of  nitrous  ether  and  potassium 
iodide  a  dangerous  combination?    Iodine  is  liber- 


prescriptions:  147 

ated  and  oxides  of  nitrogen  are  given  off.  The 
presence  of  an  acid  increases  the  reaction,  while  an 
alkali  diminishes  or  retards  it. 

Why  does  spirit  of  nitrous  ether  give  a  green 
color  with  antipyrine?  The  green  isonitroso-anti- 
pyrine  is  formed  and  is  precipitated  from  concen- 
trated solutions.  The  compound  is  not  now 
regarded  as  poisonous.  Alkali  carbonates  retard 
the  reaction. 

Why  should  prescriptions  calling  for  spirit  of 
nitrous  ether  and  drugs  containing  considerable 
tannic  acid  not  be  dispensed  as  soon  as  they  are 
mixed?  Tannic  acid  decomposes  ethyl  nitrite  or 
nitrous  acid,  liberating  oxides  of  nitrogen.  The 
reaction  may  take  place  slowly,  and  if  the  bottle 
is  stoppered,  sufficient  pressure  may  be  formed  to 
burst  it. 

Why  does  an  effervescence  occur  when  spirit  of 
nitrous  ether  is  added  to  a  solution  of  potassium 
acetate  or  other  similar  soluble  salt?  The  efferves- 
cence is  probably  due  to  the  throwing  of  the  ethyl 
nitrite  out  of  solution,  when  it  is  easily  volatihzed. 

Why  does  a  mixture  of  spirit  of  nitrous  ether, 
potassium  citrate,  and  water  separate  into  two 
layers?  Potassium  citrate  has  a  strong  affinity  for 
water  and  is  insoluble  in  alcohol.  Alcohol  tends 
to  throw  it  out  of  solution,  but  it  retains  enough 
of  water  to  keep  it  a  liquid. 

Why  is  a  mixture  of  ammonium  acetate  and 
spirit  of  nitrous  ether  a  good  combination?    Because 


148  WHYS    IN   PHARMACY. 

as  soon  as  the  nitrous  radical  is  liberated  from  ethyl 
nitrite  it  combines  with  the  annnonia  of  ammo- 
nium acetate  and  forms  ammonium  nitrite^  which 
is  nearly  as  active. 

Why  is  an  amber  bottle  better  than  a  blue  bottle 
for  silver  nitrate  solutions?  It  gives  protection 
from  the  light  as  well,  and  the  contents  can  be 
more  readily  seen. 

Why  should  sodium  phosphate  not  be  given  with 
alkaloidal  or  neutral  metallic  salts?  The  official 
phosphate  is  a  little  alkaline  and  liberates  the  alka- 
loid or  forms  an  insoluble  compound  with  the  metal. 
When  prescribed  in  such  combination  it  should 
first  be  neutralized. 

Why  does  an  alkali  citrate  increase  the  solu- 
bility of  benzoic  and  salicylic  acids?  A  partial 
decomposition  probably  results  and  some  alkali 
benzoate  and  salicylate  are  formed;  and  these,  as 
well  as  the  citric  acid  liberated,  are  soluble  in  water. 

Why  does  an  alkali  citrate  often  increase  the  solu- 
bility of  a  metallic  salt?  Alkali  citrates  often  form 
double  compounds  with  metallic  salts  and  such 
compounds  are  soluble. 

Why  does  a  mixture  of  borax  and  zinc  sulphate 
liquefy  when  rubbed  together?  Both  salts  contain 
large  amounts  of  water  of  crystallization  which  is 
liberated  by  the  chemical  reaction  induced  by  the 
rubbing. 

Why  will  one  compounder  get  a  white  precipitate, 
and  another  one  a  clear  solution,  in  filling  a  pre- 


PRESCHIPTIONS.  149 

scription  calling  for  magnesium  carbonate,  IJ  dr.; 
borax  and  citric  acid,  each  2  dr.;  water,  enough  to 
make  8  fl.  oz.?  By  adding  the  carbonate  to  the 
acid  and  water,  a  clear  solution  results  from  which 
borax  causes  no  precipitation.  By  adding  borax 
to  acid  and  water,  a  clear  solution  results,  but  the 
carbonate  does  not  dissolve  in  it  because  the  borax 
largely  neutralizes  the  acid. 

Why  does  the  addition  of  hydrocyanic  acid  to  a 
mixture  of  codeine,  tincture  of  iodine,  and  water 
dissolve  the  precipitate  and  give  a  colorless  solu- 
tion? The  precipitate  present  is  a  compound  of 
iodine  and  codeine,  and  the  color  is  due  to 
iodine.  Hydrocyanic  acid  reduces  iodine  to  an 
iodide,  thus  destroying  the  color  and  breaking  up 
the  precipitate. 

Why  does  a  mixture  of  silver  nitrate,  cocaine, 
and  water  give  a  black  precipitate?  Cocaine  takes 
away  the  nitric  acid,  precipitating  silver  as  the  oxide. 
If  cocaine  hydrochloride  is  used  a  white  precipitate 
of  silver  chloride  is  formed.  Cocaine  nitrate  should 
be  used.. 

Why  should  quinine  sulphate  be  rubbed  in  a 
mortar  before  being  put  into  capsules?  It  becomes 
less  bulky. 

Why  does  quinine  sulphate,  potassium  acetate, 
and  water  make  a  thick  mixture?  Reaction  takes 
place  and  quinine  acetate  is  probably  formed, 
although  some  recent  experimenters  claim  that 
quinine   hydrate,    acetic   acid,    and   potassium   sul- 


150  WHYS   IN   PHARMACY. 

phate  are  formed,  and  it  is  the  quinine  hydrate  that 
makes  the  mixture  so  nearly  sohd. 

Why  should  care  be  used  in  combining  quinine 
sulphate  and  potassium  iodide  in  the  same  mixture? 
Quite  frequently  an  acid  is  present,  and  if  so  it  dis- 
solves the  quinine  sulphate.  Potassium  iodide  pre- 
cipitates a  concentrated  solution  of  a  quinine  salt. 
The  acid  hberates  hydriodic  acid,  which  is  easily 
oxidized  by  the  air,  liberating  iodine.  Iodine  gives 
a  purphsh-red  precipitate  with  quinine. 

Why,  in  mixing  a  carbonate  or  hydroxide  with 
quinine  sulphate,  should  the  solutions  be  dilute  and 
cold?  The  free  alkaloid  will  be  liberated,  and  unless 
precipitated  under  the  above  conditions  it  is  likely 
to  come  down  as  a  sticky  mass. 

Why  do  two  substances  precipitate  when  sodium 
benzoate  is  added  to  an  acid  solution  of  quinine 
sulphate?  Quinine  benzoate  is  precipitated,  and 
benzoic  acid  is  liberated  and  precipitated. 

Why  does  the  addition  of  quinine  sulphate  to 
tincture  of  the  chloride  of  iron  sometimes  give  a 
yellow-brown  precipitate?  Quinine  sulphate  takes 
up  the  free  acid  to  form  a  soluble  compound  and 
so  weakens  the  acid  of  the  tincture  that  a  basic 
chloride  of  iron  is  precipitated.  The  addition  of 
more  acid  prevents  this  precipitation. 

Why  is  quinine  bisulphate  better  than  the  sul- 
phate in  making  pills?     It  is  less  bulky. 

Why  should  acid  not  be  used  to  get  quinine 
sulphate  into  solution  when  fluid  extract  of  licorice 


PRESCRIPTIONS.  151 

is  used  to  cover  up  the  bitter  taste?  The  acid 
breaks  up  the  ammonium  glycyrrhizate  and  destroys 
the  sweet  taste,  precipitating  the  bitter  glycyrrhizic 
acid.  It  is  better  to  leave  out  the  acid  and  dis- 
pense the  prescription  as  a  shake  mixture. 

Why  does  a  mixture  of  glycerin,  borax,  and  water 
give  an  acid  solution?  Borax  and  glycerin  combine  to 
form  sodium  metaborate  and  glyceryl  borate.  The  lat- 
ter compound  is  decomposed  by  water,  forming  glyce- 
rin and  boric  acid;   the  solution  is  thus  made  acid. 

Why  does  borax  precipitate  neutral  solutions  of 
metallic  and  alkaloidal  salts?  Borax  is  quite  strongly 
alkaline  and  causes  precipitation  on  this  account. 
Sometimes  the  addition  of  a  little  glycerin  is  allow- 
able and  will  prevent  precipitation. 

Why  does  a  mixture  of  mercuric  chloride  and  tar- 
tar emetic  give  a  white  precipitate?  Tartar  emetic 
reduces  mercuric  chloride  to  calomel. 

Why  does  a  mixture  of  sodium  bromide,  antipyrine, 
camphor,  and  caffeine  citrate,  when  put  into  capsules, 
liquefy  the  capsule  ?  The  chief  ingredient  concerned 
is  sodium  bromide  which  absorbs  sufficient  water  to 
cause  the  trouble.  Some  drying  powder  should  be 
used. 

Why  does  a  mixture  of  sodium  salicylate,  citrated 
caffeine,  antipyrine,  and  syrup  of  orange  give  a  white 
precipitate?  In  a  strong  solution  sodium  salicylate 
may  precipitate  antipyrine,  and  the  citric  acid  in 
citrated  caffeine  liberates  salicylic  acid,  which  is  only 
sparingly  soluble. 


152  WHYS    IN    PHARMACY. 

Why  should  bismuth  subnitrate  and  a  carbonate  or 
bicarbonate  not  be  prescribed  together  in  aqueous 
mixture?  Water  hberates  nitric  acid  from  the  bis- 
muth salt,  making  a  more  basic  salt;  and  the  nitric 
acid  in  turn  liberates  carbon  dioxide.  The  bismuth 
salt  is  converted  into  a  basic  bismuth  carbonate 
The  evolution  of  carbon  dioxide  is  slow  and  may  be 
sufficient  to  burst  the  bottle  after  it  has  been  received 
by  the  patient.  These  reactions  may  be  hurried  by 
warming  the  mixture.  Some  dispensers  use  bismuth 
subcarbonate  at  once  instead  of  waiting  for  it  to  be 
formed  as  the  result  of  the  reaction. 

Why  does  a  change  in  the  color  of  the  precipitate 
occur  when  bismuth  subnitrate  and  potassium  iodide 
are  mixed  with  water?  Different  basic  iodides  of 
bismuth  are  formed,  varying  in  color  from  brown  to 
red  and  gray. 

Why  does  bismuth  subnitrate,  when  mixed  with 
potassium  hypophosphite  and  water,  change  in  color? 
The  hypophosphite  reduces  the  bismuth,  forming 
black  insoluble  compounds. 

Why  does  an  acid,  when  added  to  a  solution  of  bis- 
muth and  ammonium  citrate,  give  a  white  precipi- 
tate? The  acid  combines  with  the  ammonia  and 
sets  free  the  insoluble  bismuth  citrate. 

Why  is  difficulty  experienced  in  making  supposi- 
tories containing  chloral  hydrate?  Chloral  hydrate 
seems  to  have  a  liquefying  action  on  oil  of  theobroma 
somewhat  similar  to  its  action  on  camphor.  Several 
other  compounds  have  a  similar  effect. 


PRESCRIPTIONS.  153 

Why  does  a  mixture  of  alcohol,  chloral  hydrate, 
and  water  sometimes  separate  into  two  layers  and 
sometimes  not?  Chloral  hydrate  combines  with  al- 
cohol, forming  chloral  alcoholate;  this  is  soluble  in 
alcohol,  but  not  in  water,  and  is  somewhat  soluble  in 
a  mixture  of  alcohol  and  water.  If  chloral  is  present 
in  comparatively  large  amounts,  and  alcohol  in  small 
amounts,  there  is  more  danger  of  separation.  Solu- 
ble salts,  such  as  potassium  bromide,  tend  to  cause 
separation. 

Why  should  scale  salts  of  iron  not  be  powdered 
before  being  dissolved  in  water?  It  makes  the  pow- 
dered salt  form  a  sticky  mass  that  dissolves  slowly. 
Warm  water  is  better  than  cold.  Boihng  water  may 
reduce  the  ferric  to  ferrous  to  some  extent. 

Why  should  scale  salts  of  iron  not  be  shaken  much 
with  water?  A  foam  is  formed  that  is  quite  per- 
sistent. 

AVhy  is  it  necessary  to  add  but  little  water  when 
sulphate  of  iron  and  potassium  bromide  are  rubbed 
together  in  making  pills  of  ferrous  bromide?  Reac- 
tion takes  place,  liberating  a  considerable  amount  of 
water  of  crystallization. 

Why  does  iodine  lose  its  therapeutic  effect  when  it 
is  given  with  drugs  containing  much  tannic  acid?  In 
the  presence  of  water  iodine  combines  with  some 
tannic  acid  and  with  the  hydrogen  of  the  water.  The 
oxygen  of  the  water  makes  an  insoluble  compound 
with  more  tannin. 

Why  does  a  mixture  of  iodine  and  ammonia  not 


154  WHYS    IN    PHARMACY. 

have  the  same  effect  that  they  do  when  apphed  sepa- 
rately? Iodine  combines  with  anmionia,  forming 
chiefly  ammonium  iodide  with  a  little  iodate.  Ex- 
plosive iodide  of  nitrogen  is  formed  under  certain 
conditions. 

Why  should  iodine  not  be  given  with  oil  of  turpen- 
tine? If  the  two  are  mixed  together  violent  chemical 
reaction  results.  Moreover,  the  iodine  probably  does 
not  have  the  same  effect  therapeutically  as  before. 

Why  should  Fowler's  solution  be  neutralized  pre- 
vious to  mixing  with  a  solution  of  a  ferric  salt?  It 
is  alkaline,  and  if  present  in  sufficient  amount  it  will 
precipitate  ferric  hydroxide,  which  will  in  turn  pre- 
cipitate potassium  arsenite. 

Why  should  Fowler's  solution  not  be  prescribed 
with  a  solution  of  mercuric  chloride?  It  reduces 
mercuric  chloride  to  calomel,  and  if  present  in  suffi- 
cient amount,  to  metallic  mercury  also.  Acidifying 
the  Fowler's  solution  will  prevent  this. 

Why  should  Fowler's  solution  not  be  prescribed 
with  a  solution  of  an  alkaloidal  salt?  Being  alka- 
line, it  liberates  the  alkaloid  which  is  precipi- 
tated. Fowler's  solution  should  be  neutralized 
before  using. 

Why  does  citric  acid  prevent  the  precipitation  of 
iron  salts  by  ammonium  hydroxide?  It  forms  double 
compounds  which  are  soluble. 

Why  does  phosphoric  acid  prevent  the  black  color 
which  usually  results  in  combining  tannic  acid  and  a 
ferric  salt?    Phosphoric  acid  seems  to  have  a  stronger 


PRESCRirTlONS.  155 

affinity  for  iron  than  tannic  acid  has,  and  thus  dis- 
places it. 

Why  should  tincture  of  ferric  chloride  and  potas- 
sium iodide  never  be  given  in  the  same  prescription? 
Iodine  is  liberated,  and  if  all  of  the  iodide  is  decom- 
posed, iodine  will  be  precipitated.  Ferric  chloride  is 
reduced  to  ferrous  chloride. 

Why  are  syrup  of  iodide  of  iron  and  potassium 
chlorate  dangerous  when  prescribed  together?  Iodine 
is  liberated  even  in  neutral  mixtures.  Adding  a  httle 
ammonia  prevents  this  liberation  for  a  time  only  and 
will  cause  precipitation  of  the  iron. 

Why  do  dilute  solutions  of  carbohc  acid  and  ferric 
salts  sometimes  fail  to  give  a  violet  coloration?  Or- 
ganic matter  and  some  neutral  salts  interfere. 

Why  should  mucilage  of  acacia  and  solution  or 
tincture  of  ferric  chloride  be  well  diluted  before  being 
mixed?  Ferric  salts  will  gelatinize  mucilage  of  acacia 
unless  in  dilute  solutions.  Alkali  citrates  prevent 
gelatinization. 

Why  may  alkali  hydroxides  or  carbonates  be  given 
with  ferric  chloride  without  apparent  incompatibihty 
if  sugar,  glycerin,  citrates,  tartrates  and  some  other 
substances  are  present?  Because  these  substances 
hold  ferric  hydroxide  in  solution. 

Why  does  phosphoric  acid  precipitate  a  solution  of 
soluble  phosphate  of  iron?  Soluble  phosphate  of 
iron  may  be  a  double  compound  of  ferric  phosphate 
and  sodium  citrate,  or  it  may  be  a  mixture  of  these, 
the  ferric  phosphate  being  soluble  in  the  citrate. 


156  WHYS    IN   PHARMACY. 

Phosphoric  acid  may  break  up  the  double  compound 
or  then  decompose  sodium  citrate,  forming  a  com- 
pound which  no  longer  acts  as  a  solvent.  The  remedy 
is  to  use  metaphosphoric  acid,  free  from  ortho-  or 
pyro-acid,  in  the  place  of  the  official  acid.  Strong 
official  phosphoric  acid  will  also  dissolve  the  precipi- 
tate. Sometimes  dilute  phosphoric  acid  will  not 
cause  precipitation. 

Why  does  calomel  with  potassium  hypophosphite 
turn  dark?  Because  the  hypophosphite  reduces  the 
calomel  to  metafile  mercury. 

Why  does  a  mixture  of  soap  and  calomel  turn  dark? 
Soap  is  alkaline  and  hence  causes  the  formation  of 
some  black  oxide  of  mercury. 

Why  must  calomel  and  potassium  iodide  not  be 
given  together  unless  the  calomel  is  in  small  amounts? 
Potassium  iodide  with  calomel  first  forms  mercurous 
iodide  and  potassium  chloride.  Mercurous  iodide, 
with  more  potassium  iodide,  is  decomposed,  forming 
mercuric  iodide  and  metafile  mercury.  Mercuric 
iodide  combines  with  more  potassium  iodide,  forming 
the  nearly  colorless  and  soluble  potassium-mercuric 
iodide,  which  is  as  active  as  mercuric  chloride. 

Why  should  antipyrine  not  be  given  with  calomel? 
Part  of  the  calomel  is  changed  to  metallic  mercury, 
and  part  is  changed  to  the  mercuric  salt,  which  is 
active.  This  reaction  is  more  fikely  to  take  place  in 
the  presence  of  sodium  bicarbonate. 

Why  should  glycerin  be  diluted  before  applying  to 
the  hands?    It  is  hygroscopic  and  absorbs  moisture 


PRESCRIPTIONS.  157 

from  the  skin  if  it  is  not  diluted,  making  the  skin  hard 
and  rough. 

Why  should  castor  oil  not  be  taken  with  oleoresin 
of  male  fern?  It  seems  to  increase  the  absorption  of 
filicic  acid  and  may  cause  symptoms  of  poisoning. 

Why  is  it  best  to  spread  a  little  olive  oil  over  the 
surface  of  a  linseed  poultice?  It  prevents  the 
poultice  from  becoming  hard  and  sticking  to  the 
skin. 

Why  should  preparations  of  iron  be  taken  through 
a  glass  tube?  Most  preparations  of  iron  contain 
acid  which  acts  on  the  enamel  of  the  teeth.  There 
is  often  a  little  sulphide  around  the  teeth  and  this 
gives  a  sulphide  of  iron  which  darkens  the  teeth. 

Why  is  ferric  hydroxide  not  precipitated  from 
ferric  salts  in  the  alkaline  contents  of  the  intestine? 
The  gases  and  the  organic  matter  present  keep  it 
in  solution. 

Why  should  arsenic  be  given  after  a  meal?  So 
as  to  dilute  it  with  the  food  and  prevent  its  irritating 
effect. 

Why  is  the  administration  of  calomel  often  fol- 
lowed by  a  dose  of  black  draught?  Calomel  acts 
on  the  upper  portion  of  the  intestine  and  black 
draught  on  the  lower  portion. 

Why  does  the  administration  of  most  organic 
acids  render  the  urine  alkaline?  The  acids  are 
eliminated  in  the  urine  as  carbonates. 

Why  does  benzoic  acid  make  the  urine  acid? 
It  is  eliminated  in  the  urine  as  hippuric  acid. 


158  WHYS   IN   PHARMACY. 

Why  is  iodoform  an  antiseptic  when  used  in 
dinics  but  not  when  experimented  with  in  the 
test-tube?  Apphed  to  the  hving  tissue  it  is  prob- 
ably dissolved  by  the  fluids  and  decomposed  by 
the  living  cells.  In  the  test-tube  these  conditions 
do  not  exist. 

Why  should  prescriptions  containing  chloral,  mor- 
phine, or  cocaine  never  be  refilled  without  the  phy- 
sician's consent?  There  is  danger  of  the  patient 
forming  a  habit. 

Why  are  morphine  and  atropine  sometimes  given 
together  although  they  are  somewhat  antagonistic 
in  physiological  action?  When  given  together  the 
atropine  is  in  small  amounts,  and  in  such  a  com- 
bination it  relieves  indigestion  and  cardiac  depression. 

Why  are  direct  emetics  of  but  little  service  in 
cases  of  poisoning  by  anaesthetics,  such  as  carbolic 
acid  and  cocaine?  Direct  emetics  act  by  irritating 
the  walls  of  the  stomach,  and  if  the  walls  are  anaes- 
thetized they  will  have  but  little  effect. 

Why  should  the  stomach-pump  be  used  with 
care,  if  used  at  all,  in  cases  of  poisoning  by  alkalies 
or  acids?  Alkalies  and  acids  often  corrode  the  walls 
of  the  esophagus,  weakening  it,  so  that  there  is  dan- 
ger of  puncturing  it  with  the  tube  of  the  pump. 

Why  should  oils  not  be  given  as  demulcents  after 
phosphorus  poisoning?  Oils  aid  the  solution  and 
the  action  of  phosphorus.  Old  oil  of  turpentine 
has  been  recommended  because  it  contains  ozone, 
which  has  an  oxidizing  effect  on  the  phosphorus. 


PRESCRIPTIONS.  159 

Why  is  charcoal  used  as  an  antidote  for  poison- 
ing by  alkaloids,  phosphorus,  and  many  metallic 
salts?  It  has  the  property  of  absorbing  these  sub- 
stances and  holding  them. 

Why  are  sulphates  given  in  case  of  poisoning  by 
carbolic  acid?  They  convert  the  acid  into  sulpho- 
carbolates  which  are  much  less  poisonous. 

Why  is  alcohol  given  for  poisoning  by  carbohc 
acid?  It  antidotes  the  action  of  carbohc  acid,  but 
it  is  not  known  whether  it  is  a  chemical  or  a  physio- 
logical antidote. 

Why  is  albumin  a  good  antidote  for  poisoning 
by  metallic  salts?  It  forms  insoluble  compounds 
with  most  metallic  salts,  but  these  should  be  removed 
as  quickly  as  possible  as  they  are  slowly  absorbed. 
In  case  of  poisoning  by  corrosive  subHmate  too 
much  albumin  redissolves  the  compound. 


MISCELLANEOUS. 

Why  do  drops  of  liquids  vary  so  much  in  size?  The 
size  depends  upon  the  shape  and  size  of  the  vessel 
from  which  dropped,  upon  adhesion,  cohesion,  rapid- 
ity of  flow,  and  viscosity. 

Why  is  a  drop  of  liquid  from  a  curved  eye-dropper 
larger  than  one  from  a  straight  dropper  having  the 
same  size  opening?  The  straight  one  is  generally 
held  at  an  angle  so  that  the  drop  falls  from  one  side 
of  the  orifice;  but  with  a  curved  dropper  the  drop 
falls  from  the  whole  circle  of  the  orifice. 

Why  is  the  center  of  gravity  of  the  beam  of  a  bal- 
ance below  the  fulcrum?  If  the  two  coincided  the 
beam  would  stay  in  any  position  in  which  it  is  placed. 
If  the  center  of  gravity  is  above  the  fulcrum  the 
beam  will  tend  to  turn  over. 

Why  is  the  center  of  gravity  of  the  beam  of  a  bal- 
ance, compared  with  the  fulcrum,  lower  in  a  balance 
intended  for  heavy  weights  than  it  is  in  more  delicate 
balances?  The  nearer  the  center  of  gravity  ap- 
proaches the  edge  of  the  fulcrum  the  more  accurate 
will  it  be,  the  slower  to  oscillate,  and  the  Hghter  the 

weight  that  will  start  it. 

160 


MISCELLANEOUS.  161 

Why  is  an  agate  knife-edge  better  than  a  steel  one? 
It  is  harder  and  does  not  corrode. 

Why  should  a  thermometer  stand  for  two  years 
before  being  graduated?  To  allow  time  for  the  glass 
to  contract. 

Why  is  mercury  a  good  fluid  for  a  thermometer? 
It  can  be  reduced  to  a  comparatively  low  tempera- 
ture without  solidifying,  will  record  a  comparatively 
high  temperature,  does  not  adhere  to  the  sides  of  the 
tube,  possesses  a  uniform  rate  of  expansion  for  each 
increment  of  heat,  and  has  great  conducting  power. 

Why  should  the  bulb  of  the  thermometer  be  a 
little  above  the  liquid  in  determining  the  boiling- 
point  of  the  liquid?  If  placed  in  the  liquid  it  will 
not  show  the  exact  boiling-point.  The  liquid  is  gen- 
erally a  little  hotter. 

Why  is  the  bumping  of  a  hot  liquid  relieved  by 
putting  in  some  irregular  or  angular  substance? 
Such  a  substance  aids  the  liberation  and  evolution 
of  the  vapor  bubbles. 

Why  was  the  temperature  of  ^'25°  C. "  adopted  in 
the  8th  revision  of  the  U.  S.  P.?  It  comes  nearer  the 
ordinary  temperature  than  15°  C.  and  can  be  more 
easily  attained. 

Why  should  a  filter- paper  never  extend  above  the 
edge  of  the  funnel?  Capillary  attraction  causes  the 
liquid  to  rise  and  crawl  over  the  funnel;  moreover, 
the  paper  cannot  be  readily  washed  under  such  cir- 
cumstances. 

Why  should  attention  be  given  in  buying  funnels 


162  WHYS    IN  PHARMACY. 

to  get  those  having  an  angle  of  sixty  degrees?  Many 
funnels  do  not  have  that  angle,  and  filter-paper  folded 
in  the  ordinary  way  makes  an  angle  of  sixty  degrees. 

Why  is  upward  filtration  sometimes  preferable  to 
downward  filtration?  By  making  a  liquid  pass  up- 
ward through  a  filter,  the  solid  matter  does  not  be- 
come packed  on  the  filter  so  much  and  clog  filtration. 

Why  is  4°  C.  specified  as  the  temperature  at  which 
1  cc.  shall  weigh  1  gram?  At  4°  C.  water  has  its  maxi- 
mum density,  a  given  volume  being  lighter  when 
either  above  or  below  4°  C. 

Why  does  dissolving  a  solid  in  water  produce  cold? 
Heat  is  absorbed;  active  heat  is  changed  to  latent 
heat  when  a  solid  changes  from  such  to  a  liquid  con- 
dition unless  there  be  chemical  reaction. 

Why  does  the  solution  of  anhydrous  salts  in  water 
produce  heat?  It  is  generally  considered  that  chem- 
ical reaction  takes  place,  the  water  of  crystallization 
combining  with  the  salt. 

Why  do  some  solids  in  dissolving  produce  more 
cold  than  others?  Generally  the  more  rapid  the  solu- 
tion the  greater  the  amount  of  cold  produced. 

Why  does  dissolving  a  gas  in  water  produce  a  rise 
in  temperature?  When  a  gas  changes  to  a  Hquid, 
latent  heat  is  changed  to  active  heat. 

Why,  in  powdering  a  substance,  is  it  better  to 
remove  the  finer  particles  by  frequent  sifting?  If 
the  finer  particles  are  left  in  they  become  more  or 
less  packed  around  the  larger  ones  and  protect  them 
from  being  powdered. 


MISCELLANEOUS.  163 

Why  does  powdering  a  soluble  substance  aid  its 
solution  in  a  liquid?  A  greater  surface  is  exposed  to 
the  solvent  action  of  the  liquid. 

Why  does  stirring  aid  solution?  The  liquid  in  im- 
mediate contact  with  the  solid  becomes  saturated,  or 
nearly  so,  and  stirring  causes  this  to  be  displaced  by 
liquid  that  is  less  saturated. 

Why  does  heat  generally  aid  solution?  Heat  causes 
greater  molecular  motion,  favors  molecular  separa- 
tion, and  causes  currents  to  be  formed  in  the  liquid. 

Why  is  albumin  used  in  clarifying  liquids?  Be- 
cause it  can  be  intimately  mixed  with  the  liquid,  and 
then  when  it  is  coagulated  it  carries  the  suspended 
matter  down  with  it. 

Why  does  heating  sometimes  clarify  a  Uquid?  Heat 
coagulates  albumin  if  present,  and  this  acts  mechan- 
ically in  enveloping  the  suspended  matter.  Heat 
lessens  the  viscosity  of  the  hquid,  allowing  the  mat- 
ter to  separate  more  readily.  The  sohd  matter  may 
also  be  carried  to  the  top  by  the  globules  of  vapor 
formed. 

Why  does  fermentation  sometimes  clarify  a  liquid? 
If  albumin  is  present  it  is  coagulated  by  the  alcohol 
and  acid  formed. 

Why  does  rapidity  of  evaporation  depend  upon  the 
extent  of  surface  exposed  to  the  air  when  a  liquid  is 
evaporated  below  its  boiling-point?  The  formation 
of  vapor  takes  place  at  the  surface  which  is  exposed 
to  air. 

Why  does  rapidity  of  evaporation  depend  upon  the 


164  WHYS   IN   PHARMACY. 

extent  of  surface  exposed  to  heat  when  a  liquid  is 
evaporated  by  boiling?  The  formation  of  vapor  un- 
der such  circumstances  takes  place  chiefly  at  the 
surface  exposed  to  heat. 

Why  do  shallow  ve^.sels  favor  evaporation?  There 
is  less  weight  of  liquid  above  the  heat,  and  therefore 
less  resistance  to  the  escape  of  bubbles. 

Why  are  stone  vessels  better  than  glass  for  crys- 
tallizing? The  roughness  of  the  surface  favors  crys- 
tallization. 

Why  should  a  precipitating  jar  be  wider  at  the 
bottom  than  at  the  top?  So  that  the  precipitate  on 
settling  will  not  adhere  to  the  sides  of  the  jar. 

Why  is  a  non-luminous  flame  hotter  than  a  lumi- 
nous flame?  In  a  non-luminous  flame  all  of  the 
carbon  is  consumed  while  it  is  not  in  a  luminous 
flame. 

Why  is  the  cold  water  made  to  enter  the  lower 
opening  of  a  Liebig  condenser  rather  than  the  top? 
As  water  becomes  heated  it  naturally  rises  and  the 
cold  water  pushes  it  out  instead  of  mixing  with  it. 
The  lower  end  of  the  condenser  from  which  the  con- 
densed vapor  flows  is  thus  kept  at  the  lowest  tem- 
perature possible. 

Why  is  a  worm  condenser  better  than  a  straight 
one?  Sometimes  in  case  of  a  straight  condenser  the 
vapor  passes  through  mthout  touching  the  sides  of 
the  tube  and  without  condensing.  In  a  worm  con- 
denser the  vapor  is  made  to  continually  change  its 
course  and  so  come  in  contact  with  the  cool  tube. 


EQUATIONS  SHOWING  THE  CHEMICAL  RE- 
ACTIONS WHICH  TAKE  PLACE  IN  MAKING 
THE  PREPARATIONS  FOR  WHICH  THE 
PHARMACOPCEIA  GIVES  DIRECTIONS. 

Dilute  Hydriodic  Acid. 


KI      + 


Potassium 
iodide 


H2C4H4O6 

Tartaric  acid 


KH2PO2  +    H2C4H4O6 

Potassium  Tartaric 

hypophos-  acid 

phite 


=     HI     + 

Hydriodic  acid 


KHC4H4O6. 

Potassium 
bitartrate 


=     H3PO2     +    KHC4H4O6. 


Hypophos- 
phorous 
acid 


Potassium 
bitartrate 


Dilute  Hydrocyanic  Acid. 
AgCN     +     HCl     =     HCN     +    AgCl. 


Silver 
cyanide 


Hydrochlo- 
ric acid 


Hydrocy- 
anic acid 


Silver 
chloride 


Nitrohydrochloric  Acid. 


HNO3     +     3HC1     =     NOCl 


Nitric 
acid 

2HNO3 

Nitric 
acid 


Hydrochlo- 
ric acid 


Nitrosyl  mono- 
chloride 


+       CI2 

Chlorine 


+ 


2H2O. 

Water 


+  6HC1   = 

Hydro- 
chloric acid 


2NOCI2 

Nitrosyl 
dichloride 


+    CI2     +    4H2O. 

Chlorine  Water 


Probably  both  reactions  take  place. 


165 


166  WHYS   IN    PHARMACY. 

Aromatic  Sulphuric  Acid, 
C2H5OH   +  H2SO4   =  C2H5HSO4   +  H2O; 

Alcohol  Sulphuric  Ethyl  acid  Water 

acid  sulphate 

and  also,  to  some  extent, 

2C2H5OH    +   H2SO4   =    (C2H5)20   +   H2SO4    +   H2O. 

Alcohol  Sulphuric  Ether  Sulphuric  Water 

acid  acid 


Sulphurous  Acid. 


4H2S04 

+  C2  = 

4SO2 

+      2CO2      +      4H2O 

Sulphuric 
acid 

Carbon 

Sulphur 
dioxide 

Carbon                 Water 
dioxide 

Aluminum  Hydroxide, 

Al2K2(S04)4  +3Na2C03  +3H2O  = 

Alum  Sodium  Water 

carbonate 


2A1(0H)3  +K2SO4  +3Na2S04  +3CO2. 

Aluminum         Potassium  Sodium  Carbon 

hydroxide  sulphate  sulphate  dioxide 


Fused  Silver  Nitrate. 

AgNOs     +     HCl     =     AgCl     +  HNO3. 

Silver                    Hydro-                    Silver  Nitric 

nitrate              chloric  acid              chloride  acid 


Bismuth  Citrate. 
BiONOs  +  H3C6H5O7  =  BiCeHsOy  +  HNO3  +  H2O. 

Bismuth  Citric  acid  Bismuth  Nitric  Water 

subnitrate  citrate  acid 


EQUATIONS    SHOWING    CHEMICAL   REACTIONS.      167 


Sulphurated  Lime. 


CaS04 

+  3C  = 

=  CaS   +  2C0   +  CO2. 

Calcium 

Carbon 

Calcium          Carbon           Carbon 

sulphate 

sulphide       monoxide        dioxide 

Purified  Animal  Charcoal. 


Ca3(P04)2    +  4HC1   =  Ca(H2P04)2    +  2CaCl 

Calcium  Hydro- 

phosphate  chloric  acid 


Calcium  acid 
phosphate 


Calcium 
chloride 


and 


CaCOs   +  2HC1   =  CaCla   +  CO2   +  H2O. 

Calcium  Hydro-  Calcium  Carbon  Water 

carbonate        chloric  acid  chloride  dioxide 


Lead  Plaster. 


2NaCi8H3302  +Pb(C2H302)2  = 

Sodium  oleate  Lead  acetate 


Pb(Ci8H3302)2  +2NaC2H302. 

Lead  oleate  Sodium  acetate 


Saccharated  Carbonate  of  Iron. 


FeS04  +  2NaHC03  =  reC03+  Na2S04+C02+H20. 


Ferrous 
sulphate 


Sodium 
bicarbonate 


Ferrous 
carbonate 


Sodium 
sulphate 


Carbon     Water 
dioxide 


Ferric  Hydroxide. 


Fe2(S04)3  +6NH40H  =  2Fe(OH)3  +3(NH4)2S04. 


Ferric 
sulphate 


Ammonia 


Ferric 
hydroxide 


Ammonium 
sulphate 


168 


WHYS   IN    PHARMACY. 


Glycerite  of  Boroglycerin. 
C3H5(0H)3  +H3BO3  ^CsHsBOs  +3H2O. 

Glycerin  Boric  acid    Glyceryl  borate       Water 


Yellow  Iodide  of  Mercury. 


3Hg   +  4HNO3   =  3HgN03   +  NO   +  2H2O. 

Mercury  Nitric  acid  Mercurous         Nitric  oxide       Water 

nitrate 

HgN03     +     KI     =     Hgl     +     KNO3. 


Mercurous 
nitrate 


Potassium 
iodide 


Mercurous 
iodide 


Potassium 
iodide 


If  potassium   iodide    is   in   excess  the   following 
reactions  take  place: 

2HgI     +     KI     =     Hg     +     Hgl2     +     KI. 


Mercurous 
iodide 


Potassium 
iodide 


Mercury 


Mercuric 
iodide 


Potassium 
iodide 


Hgl2 

Mercuric 
iodide 


+     2KI     =     Hgl2-2KI. 

Potassium         Potassium  mercuric 
iodide  iodide 


Red  Iodide  of  Mercury. 


HgCl2 

Mercuric 
chloride 


+     2KI 


Potassium 
iodide 


HgT2     +     2KC1. 


Mercuric 
iodide 


Potassium 
chloride 


Hgl2 

Mercuric 
iodide 


+     2KI     = 

Potassium 
iodide 


Hgl2-2KI. 

Potassium 

mercuric 

iodide 


8HgCl2     +     2KI     = 


Mercuric 
chloride 


Potassium 
iodide 


Hgl2-2HgCl2     +     2KC1. 

Mercuric  Potassiurn 

iodochloride  chloride 


If  too  much  potassium  iodide  is  used  the  second 
reaction  takes  place,  and  if  tlie  mercuric  chloride  is 
in  excess  the  last  reaction  takes  place. 


EQUATIONS    SHOWING    CHEMICAL    REACTIONS.      1G9 

Yellow  Oxide  of  Mercury. 
HgCl2   +  2NaOH  =  HgO   +  2NaCl   +  H2O. 

Mercuric  Sodium  Mercuric  Sodium  Water 

chloride  hydroxide  oxide  chloride 

4HgCl2  +6NaOH  =  HgCl2  •  3HgO  +6NaCl  +3H2O, 

Mercuric  Sodium  Basic  mercuric  Sodium  Water 

chloride        hydroxide  chloride  chloride 

if  HgCl2  is  in  excess. 

Ammoniated  Mercury. 
HgCl2  +  2NH4OH  =  NH4CI  +  NH2HgCl  +  2H2O. 

Mercuric  Ammonia  Ammonium         Ammoniated  Water 

chloride  chloride  mercury 


Infusion  of  Wild  Cherry. 
C20H27NO11  +2H2O  +emulsin  = 

Amygdalin  Water 

2C6H12O6  +HCN  +C6H5COH  +emulsin. 

Glucose         Hydrocy-         Benzalde- 
anic  acid  hyde 

Ammonia  Liniment. 

C3H5(Ci8H3302)3  +3NH40H  = 

Olein  Ammonia 

3NH4C,«H3302  +C3H5(0PI)3, 

Ammonium  oleate  Glycerin 

and 

HC18H3302  +  NH40H  =  NH4C18H3302  +  H20. 

Oleic  acid  Ammonia  Ammonium  oleate  Water 


Solution  of  Arsenous  Acid. 
AS2O3     +    3H2O     =    2H3ASO3. 

Arsenous  oxide  Water  Arsenous  acid 


170 


WHYS  IN    PHARMACY. 


Solution  of  Ammonium  Acetate. 


NH4HCO3  •  NH4NH2CO2  -f  3HC2H3O2  = 

Acetic  acid 


Ammonium  bicarbonate 
and  carbamate 


3NH4C2H3O2  +2CO2  +H2O. 


Ammonium 
acetate 


Carbon 
dioxide 


Water 


Solution  of  Lime. 


CaO   +  H2O   =  Ca(0H)2. 


Lime 


Water       Calcium  hydroxide 


Compound  Solution  of  Chlorine. 
KCIO3    +    6HC1    =    KCl    +    3CI2    +    3H2O, 


potassium 
chlorate 


Hydrochloric       Potassium       Chlorine  Water 

acid  chloride 


and 


2KCIO3   +  4HC1  =  2KC1  +  2CIO2  +  CI2  +  2H2O. 

Potassium       Hydrochloric     Potassium         Chlorine       Chlorine        Water 
chlorate  acid  chloride  peroxide 


Solution  of  Ferric  Chloride. 


Fe     +     2HC1     =     FeCl2     +      H^ 


Iron 


Hydro- 
chloric acid 


Ferrous 
chloride 


Hydrogen 


3FeCl2  +HNO3  +3HC1  =  3FeCl3  +N0  +2H2O. 


Ferrous  Nitric  Hydro-  Ferric  Nitric 

chloride  acid       chloric  acid    chloride        oxide 


Water 


Solution  of  Iron  and  Ammonium  Acetate. 


FeCls  +3NH4C2H302  =  Fe(C2H302)3  +3NH4CI. 


Ferric 
chloride 


Ammonium 
acetate 


Ferric 
acetate 


Ammonium 
chloride 


(To  some  extent.) 


EQUATIONS   SHOWING    CHEMICAL    REACTIONS.    171 

Solution  of  Ferric  Subsulphate. 
12FeS04  +3H2SO4  +4HNO3  = 

Ferrous  Sulphuric  Nitric 

sulphate  acid  acid  ♦ 

3Fe40(S04)5  +4N0  +5H2O. 

Ferric  Nitric         Water 

subsulphate  oxide 

Solution  of  Ferric  Sulphate. 
6FeS04  +3H2SO4  +2HNO3  = 

Ferrous  Sulphuric  Nitric 

sulphate  acid  acid 

3Fe2(S04)3+2NO+4H20. 

Ferric  Nitric  Water 

sulphate  oxide 

Solution  of  Mercuric  Nitrate. 
HgO    +  2HNO3   =  Hg(N03)2   +  H2O. 

Mercuric  Nitric  Mercuric  Water 

oxide  acid  nitrate 


Solution  of  Magnesium  Citrate. 
4MgC03Mg(OH)2+5H3C6H507  = 

Magnesium  Citric  acid 

carbonate 


5MgHC6H507 +4CO2  +6H2O. 

Magnesium  Carbon  Water 

acid  citrate  dioxide 


2KHCO3  +H3C6H507  =  K2HC6H507  +2CO2  +2H2O. 

Potassium  Citric  acid  Potassium  Carbon        Water 

bicarbonate  acid  citrate  dioxide 

(Probably). 


172 


WHYS   IN   PHARMACY. 


Solution  of  Lead  Subacetate. 

Pb(C2H302)2  +PbO  =  Pb20(C2H302)2: 

Lead  Lead  Lead  sub- 

acetate       *  oxide  acetate 


Solution  of  Potassium  Arsenite. 

AS2O3  +  4KHCO3  =  2K2HASO3  +  H2O  +  4CO2; 

Arsenous             Potassium                  Potassium                Water  Carbon 

oxide               bicarbonate               acid  arsenite  dioxide 


or, 


AS203  +  2KHC03  +  H20  = 

=    2KH2ASO3    +    2CO2; 

Arsenous              Potassium              Water 

Potassium                Carbon 

oxide              bicarbonate 

acid  arsenite              dioxide 

or, 


AS2O3  +  2KHCO3  =  2KASO2  +  H2O   +  2CO2; 

Potassium  Water  Carbon 

met-arsenite  dioxide 


Arsenous 
oxide 


Potassium 
bicarbonate 


and 


2KHCO3   +  boiling 

Potassium 
bicarbonate 


K2CO3     +    H2O     +    CO2. 

Potassium  Water  Carbon 

carbonate  dioxide 


It  is  not  definitely  known  which  of  the  first  three 
reactions  take  place.  The  solution  is  alkaUne  from 
the  potassium  carbonate  formed. 


Solution  of  Potassium  Citrate. 
3KHCO3  +H3C6H507  =  K3C6H507  +  3H2O  +3C02. 

Potassium  Citric  acid  Potassium  Water        Carbon 

bicarbonate  citrate  dioxide 


EQUATIONS    SHOWING    CHEMICAL   REACTIONS.      173 


Ca(0Cl)2 

Calcium 
hypochlorite 


Solution  of  Chlorinated  Soda. 


+     CaCl2 

Calcium 
chloride 


+     2Na2C03  = 


Sodium 
hypochlorite 


Sodium 
carbonate 


2NaOCl     +     2NaCI     +     2CaC03. 


Sodium 
chloride 


Calcium 
carbonate 


Solution  of  Zinc  Chloride. 


Zn     +     2HC1  =  ZnCl2 

Zinc  Hydro-  Zinc 

chloric  acid  chloride 


Fe     +     2HC1     = 

Iron  Hydro- 

chloric acid 

3FeCl2  +  3HC1   +  HNO3  = 

Ferrous  Hydro-  Nitric 

chloride     chloric  acid  acid 


FeCl2 

Ferrous 
chloride 


+        H2. 

Hydrogen 

+       H2. 

Hydrogen 


3FeCl3   +  NO   +  2H2O. 

Ferric  Nitric  Water 

chloride  oxide 


2FeCl3  +3ZnC03  +3H20  =  2Fe(OH)3  +3ZnCl2  +3CO2. 

Ferric  Zinc  Water  Ferric  Zinc  Carbon 

chloride      carbonate  hydroxide  chloride         dioxide 

The  last  three  reactions  take  place  if  iron  is  present 
as  an  impurity. 

Precipitated  Manganese  Dioxide. 
MnS04  +  2NH4OH  +  H2O2  = 


Manganese 
sulphate 


Ammonia 


Hydrogen 
dioxide 


Mn02  +  (NH4)2S04  +2H2O. 

Manganese        Ammonium  Water 

dioxide  sulphate 


Mass  of  Ferrous  Carbonate. 


FeS04   +  NasCOs  =  FeC03   +  Na2S04. 

Ferrous  Sodium  Ferrous  Sodium 

sulphate  carbonate  carbonate  sulphate 


174 


WHYS   IN  PHARMACY. 


Compound  Iron  Mixture. 
FeS04  +  K2CO3  =  FeCOs   +  K2SO4. 


Ferrous 
sulphate 


Potassium 
carbonate 


Ferrous 
carbonate 


Potassium 
sulphate 


Resin  in  myrrh  +Potassium  carbonate  = 

Resin  soap  +  Carbon  dioxide. 

Mixture  of  Rhubarb  and  Soda. 

Resin  in  rhubarb  +  Sodium  bicarbonate  = 

Resin  soap  +  Carbon  dioxide. 

Oleate  of  Atropine. 

C17H23NO3  +HCi8H3302  =  Ci7H23N03HCi8H3302. 

Atropine  Oleic  acid  Atropine  oleate 


Oleate  of  Mercury. 

HgO     +    2HC18H33O2    =    Hg(Ci8H3302)2     +    H2O. 


Mercuric 
oxide 


Oleic  acid 


Mercuric  oleate 


Water 


Pills  of  Carbonate  of  Iron. 


FeS04 

Ferrous 
sulphate 


+       K2CO3 

Potassium 
carbonate 


=     FeCOs 

Ferrous 
carbonate 


+       K2SO4. 

Potassium 
sulphate 


Pills  of  Iodide  of  Iron. 
Fe     +     I2     =     Fel2. 

Iron  Iodine        Ferrous  iodide 


Compound  Effervescing  Powder. 
2NaHC03  +H2C4H406  =  Na2C4H406  +2CO2  +2H2O. 


Sodium 
bicarbonate 


Tartaric 
acid 


Sodium 
tartrate 


Carbon 
dioxide 


Water 


EQUATIONS   SHOWING    CHEMICAL    REACTIONS.      175 


Spirit  of  Nitrous  Ether. 


2NaN02     +     H2SO. 


Sodium 
nitrite 


Sulphuric 
acid 


Na2S04 

Sodium 
sulphate 


+ 


2HNO2. 

Nitrous 
acid 


C2H5OH 

Alcohol 


+ 


HNO2 

Nitrous  acid 


C2H5NO2 

Ethyl  nitrite 


+       H2O. 

Water 


Aromatic  Spirit  of  Ammonia. 
NH4HCO3  •  NH4NH2CO2  +NH4OH  =  2(NH4)2C03. 

Ammonium  bicarbonate  Ammonia  Ammonium 

and  carbamate  carbonate 


Iodide  of  Sulphur. 

12+82     =     I2S2. 

Iodine  Sulphur     Iodide  of  sulphur 


Washed  Sulphur. 


H2SO4     +    2NH4OH     =     (NH4)2S04 
Sulphuric  Ammonia  Ammonium 

acid  I  sulphate 


+    2H2O. 

Water 


AS2S3 +6NH40H=  (NH4)3As03  +  (NH4)3AsS3  +3H0. 

Arsenous         Ammonia  Ammonium  Ammonium         Water 

sulphide  arsenite  sulphar- 

senite 


Precipitated  Sulphur. 


CaO 

Linie 


+ 


3Ca(OH)2   +  12s 

Calcium  Sulphur 

hydroxide 


H2O     =     Ca(0H)2. 

Water  Calcium  hydroxide 

=  2CaS5   +  CaS203   +  3H2O. 

Calcium  Calcium  Water 

penta-  thiosui- 

sulphide  phate 


176 


WHYS   IN   PHARMACY. 


2As2S3+6Ca(OH)2  =  Ca3(As03)2  +  Ca3(AsS3)2  +  6H20. 

Arsenous  Calcium  Calcium  Calcium  Water 

sulphide  hydroxide  arsenite  sulph- 

arsenite 


CaS5     +     2HC1     = 


Calcium 

penta- 

sulphide 


Hydro- 
chloric acid 


CaCl2 

Calcium 
chloride 


+     4S 

Sulphur 


+ 


H2S. 

Hydrogen 
sulphide 


Glycerin  Suppositories. 

Na2C03  +2HCi8H3502  =  2NaCi8H3502  +CO2  +H2O. 

Sodium  Stearic  acid  Sodium  Carbon     Water 

carbonate  stearate  dioxide 


Syrup  Calcium  Lactophosphate. 


CaCOg  +2HC3H5O3  =  Ca(C3H503)2  +CO2  +H2O. 


Calcium 
carbonate 


Lactic  acid 


Calcium 
lactate 


Carbon 
dioxide 


Water 


Ca(C3H503)2   +  H3PO4  =  CaHP04   +  2HC3H5O3. 

Calcium  Phosphoric  Calcium  Lactic  acid 

laetate  acid  acid  phosphate 


Syrup  of  Lime. 


CaO+H20=-Ca(HO)2. 

Lime       Water         Calcium 
hydroxide 


Syrup  Iodide  of  Iron. 


Fe   +  I2  =  Fel2. 

Iron        Iodine        Ferrous 
iodide 


EQUATIONS   SHOWING    CHEMICAL    REACTIONS.      177 

Tincture  of  Ferric  Chloride. 
C2H5OH  +  HCl  =  C2H5CI   +  H2O,  (probably). 

Alcohol  Hydro-  Ethyl  Water 

chloric  acid  chloride 

Ointment  of  Mercuric  Nitrate. 
3Hg   +  8HNO3  =  3Hg(N03)2   +  2N0   +  4H2O. 

Mercury  Nitric  Mercuric  Nitric  Water 

acid  nitrate  oxide 

Lard  +  Nitric  a  cid  =  Elaidin+ Nitric  oxide. 


INDEX. 


PAGE 

Acacia 13,  142 

mucilage  of 41,  142,  155 

syrup  of 64 

Acid,  acetic 83 

arsenous 94, 1 57 

solution  of 29,  169 

benzoic 84, 148, 157 

boric 84 

carbolic 121,  142,  143,  146,  155,  159 

chromic 96 

citric 84, 154 

syrup  of 64 

hydriodic  acid 85,  165 

hydrochloric 85 

hydrocyanic 86, 149,  165 

hypophosphorous 86 

lactic 87 

meconic 136 

nitric 87 

nitrohydrochloric 87, 165 

phosphoric 88,  154,  155 

salicylic 89,  148 

elixir  of 9 

ointment  of 80 

179 


ISO  INDEX, 

PAGE 

Acid,  sulphuric 89 

aromatic 90, 166 

sulphurous 91,  166 

tannic 91, 147 

ointment  of 79 

suppositories  of 63 

Acids 83 

Aconite,  assay  of 136 

Aconitine 128, 136 

Albumin 159 

Alcohol 117, 153, 159 

Alkaloids 126 

definition  of 126 

estimation  of 127 

preservation  of 126 

Aloes 117 

extract  of 23 

Alum 92 

Aluminum  hydroxide 92,  166 

Ammonia,  liniment  of 27, 169 

spirit  of 60 

aromatic 60,  175 

water  of 3,  153 

Ammonium  acetate 147 

solution  of 29,  70 

benzoate 93 

carbonate 93,  143,  145 

iodide 93 

Antidotes  to  poisons 158 

Antimony  and  potassium  tartrate 93,  151 

Antipyrine 143,  146, 147,  151 

Apomorphine  hydrochloride 136 

Arsenic  trioxide 94,  157 

Atropine 128 

oleate  of 174 

Balances 1 60 

Bay,  oil  of 49 


INDEX.  181 

PAGE 

Bay,  spirit  of 61 

Bay  rum 61 

Beeswax 119 

Belladonna 117 

extract  of 23 

fluid  extract  of 20 

Bicarbonate  of  potassium 109 

Bicarbonates  of  alkalies 140,  141 

Bismuth  and  ammonium  citrate 95 

elixir  of 10 

citrate 94, 166 

subnitrate 95^  152 

Bitter-almond  oil 47 

water 4 

Blue  mass 39 

ointment 81 

Borax 148,  149,  151 

Bumping 161 

Caffeine  citrate 118 

effervescing 58 

Calcium  carbonate 95 

iodide,  syrup  of 69 

lactophosphate,  syrup  of 65  176 

oxide 95 

salts 95 

Calomel 103, 156, 157 

Camphor 118, 143 

water 4 

Cannabis  indica 118 

Cantharides  cerate g 

collodion 7 

Carbonates,  alkali I44  1 55 

Cardamom 12o 

Carmin  in  elixirs 9 

solution  of 37 

Cascara  sagrada 123 

aromatic  fluid  extract  of 21 


182  INDEX. 

PAGE 

Cerate 6 

cantharides 6 

lead  subacetate 6 

resin 6 

Cerates 5 

Chalk  mixture 40 

prepared 96 

Charcoal,  animal 118, 159, 167 

Chemicals 83 

Chloral  hydrate 141, 146,  152, 153,  158 

Chlorinated  soda,  solution  of 35,  36,  173 

Chlorine,  compound  solution  of 31, 170 

water  of 4 

Chloroform 119 

mulsion  of 14 

niment  of 28 

water  of 5 

Chondrus 119 

mucilage  of 42 

Chromium  trioxide 96 

Cinchona 119 

assay  of 128 

detannated  tincture  of 75 

elixir  of 10 

infusion  of 27 

Citrine  ointment 81, 177 

Clarification 163 

Coating  pills 52 

Cocaine 149, 158 

Cochineal •  •    119 

Codeine 149 

Colchicum,  assay  of 136 

extract  of 24 

Collodion 7 

cantharides 7 

flexible 7 

Condensers 164 

Conium,  assay  of 136 


INDEX.  183 

PAGE 

Conium,  fluid  extract  of 20 

Corrosive  sublimate 102, 151 

solution  of 141 

tablets  of 141 

Cotton 121 

Court-plaster 12 

Creosote 120 

Crystallization 164 

Cubebs 120 

oleoresin  of 43 

Decoctions 8 

Diachylon  ointment 80 

Dobell's  solution 38 

Donovan's  solution 30 

Dover's  powder 56 

Drops 160 

Drugs,  assay  of 126 

organic 117 

powdered 117 

Elixir  of  ammonium  valerate 9 

anise 10 

aromatic 8 

bismuth 10 

buchu t 10 

cinchona 10 

digestive,  compound 10 

gentian 11 

iron,  quinine,  and  strychnine 9 

pepsin  and  bismuth 11 

salicylic  acid 9 

soluble  phosphate  of  iron 9 

yerba  santa  aromatic. 10 

Elixirs 8 

carmin  in 9 

Emetics 1 58 

Emulsion  of  chloroform 14 

cod-liver  oil 14 


184  INDEX. 

PAGB 

Emulsions 12 

Equations. 165 

Ergot 120 

extract  of 24 

fluid  extract  of 20 

Ether 117 

Eucalyptus 120 

oil  of 48 

Euphorin 143 

Evaporation 163 

Exalgin 143 

Excipients,  pill 51 

Extract  of  aloes 23 

belladonna 23 

colchicum 24 

colocynth 24 

compound 24 

ergot. 24 

gentian 24 

glycyrrhiza 24 

hyoscyamus 23 

logwood 25 

nux  vomica 25 

quassia 25 

physostigma 23 

Extracts 22 

from  fluid  extracts 23 

glycerin  in 23 

licorice-root  in 23 

variation  in 22 

Filtration 134,161,162 

Flame,  non-luminous 1 64 

Fluid  extract  of  belladonna 20 

cascara,  aromatic 21 

conium 20 

ergot 20 

glycyrrhiza 20 

lupulin 20 


INDEX.  185 

PAGE 

Fluid  extract  of  mix  vomica 21 

sangLiinaria 21 

senega 21 

taraxacum 22 

triticum 22 

wild  cherry 21 

Fluid  extracts 14 

by  repercolation. 19 

evaporation  in  making 17 

glycerin  in 19 

precipitation  of 18 

preservation  of 19 

Fowler's  solution 34,  154,  172 

Funnels 161 

Gentian 120 

elixir  of 11 

extract  of 24 

Ginger 125 

solution  of 38 

Ginseng 121 

Glycerin 121, 151, 156 

in  extracts 23 

in  fluid  extracts 19 

suppositories  of 63,  176 

Glycerite  of  boroglycerin 26, 168 

starch 25 

Glycyrrhiza 121 

compound  powder  of 56 

extract  of 24 

fluid  extract  of 20 

in  extracts 23 

Glycyrrhizin 121 

Gold  and  sodium  chloride 94, 146 

Granular  effervescing  powders 57 

Honey 1 45 

Hydrastine 137 

Hydrogen  dioxide  water 5 


186  INDEX. 

PAGE 

Hyoscyamine 182 

Hyoscyamus,  extract  of 23 

Hypodermic  solutions » 141 

Ichthyol 146 

suppositories  of 63 

Infusion  of  cinchona 27 

digitalis 27 

wild  cherry 27,  169 

Infusions 26 

Inorganic  compounds 92 

Iodine 153, 154 

compound  solution  of 33 

ointment  of 81 

pills  of 1 53 

tincture  of 73 

Churchill's 76 

decolorized 76 

Iodoform 158 

ointment  of 81 

suppositories  of 63 

Irish  moss 119 

mucilage  of 42 

Iron  and  ammonium  citrate 98, 1 43 

tartrate 98 

quinine  citrate 98 

strychnine  citrate 98 

carbonate,  mass  of 38, 173 

pills  of 53, 174 

saccharated 96, 167 

chloride 97 

solution  of 31 , 1 70 

tincture  of 72, 155, 177 

ethereal 75 

citrate 97 

solution  of 97 

dialyzed,  solution  of 32 

hydroxide 99, 157, 167 


INDEX.  187 

PAGE 

Iron  hypophosphite 98 

solution  of 37 

syrup  of 70 

iodide ' 99 

pills  of 53, 174 

saccharated 99 

solution  of 37, 155 

syrup  of 65, 1 76 

mixture,  compound 40, 174 

phosphate,  soluble 100, 155 

pyrophosphate,  soluble 100 

quinine  and  strychnine,  elixir  of 9 

syrup  of 66 

reduced 101 

salts  of 97 

scale 153 

subsulphate,  solution  of 32, 171 

sulphate 100, 143 

dried 100 

granulated 101 

solution  of 171 

Kino 121 

tincture  of 73 

Labarraque's  solution 35, 36, 173 

Lard 79 

oil 45 

Laudanum 74, 134, 145 

Lead  acetate 108, 143 

iodide 108 

nitrate 108 

oleate 42 

oxide 108 

plaster 12, 167 

salts 108 

subacetate,  cerate  of 6 

solution  of 34, 172 


188  INDEX. 

PAGE 

Lead  water 145 

Licorice 121 

compound  powder  of 56 

extract  of 24 

fluid  extract  of 20 

in  extracts 23 

Lime 95 

chlorinated 95 

solution  of 30, 1 70 

sulphurated 96, 167 

syrup  of 65, 1 76 

Liniment  of  ammonia 27, 169 

chloroform 28 

soap 28 

Liniments 27 

Lozenges 77 

Lycopodium 121 

Magnesium  carbonate 107 

citrate,  effervescing 59 

solution  of 33, 171 

oxide 107 

Male  fern 117 

oleoresin  of 43, 157 

Mandrake,  resin  of 59 

Mass  of  copaiba 39 

iron  carbonate 38, 173 

mercury 39 

Mayer's  reagent 144 

Menthol 143 

Mercuric  chloride 102, 151 

solution  of 141 

tablets  of 141 

iodide 104, 143, 168 

nitrate,  solution  of 33, 172 

ointment  of 80, 1 77 

oxide 104, 169 

ointment  of 81 


INDEX.  .     189 

PAGE 

Mercuric  subsulphate 105 

Mercurous  chloride 103, 156,  157 

iodide 103, 143, 168 

Mercury,  ammoniated 106, 169 

in  thermometers 161 

mass  of 39 

ointment  of 80 

oleate  of 42, 174 

plaster  of 12 

salts  of 102 

with  chalk 106 

Miscellaneous 160 

Mixture,  chalk 40 

chloral  and  potassium  bromide 40 

iron,  compound 40, 174 

rhubarb  and  soda 1 74 

Morphine 135,  158 

Monsel's  solution 32, 171 

Mucilage  of  acacia 41, 142, 155 

Irish  moss 42 

tragacanth 41 

Mustard 124 

oil  of 50 

paper  of 6 

Naphtol 143 

Narcotine 135 

Nitroglycerin,  spirit  of 61 

Nitrous  ether,  spirit  of 59 

Nutmegs 121 

Nux  vomica,  assay  of 130 

extract  of 25 

fluid  extract  of 21 

tincture  of 74 

Oil  of  almond,  expressed 45 

bay 49 

bitter  almond 47 


190  INDEX. 

PAGE 

Oil  of  cajuput 48 

cassia 48 

castor 46, 157 

cloves. 48 

cod  liver 45 

emulsion  of 14 

cottonseed 45 

eucalyptus 48 

juniper 48 

lard 45 

lemon 48 

linseed 45 

mustard 50 

olive. 46, 157 

orange 49 

patchouly 49 

peppermint 49 

phosphorated 46 

pimenta 49 

rose 49 

rosemary 48 

sandalwood 49 

theobroma 62, 152 

turpentine 50, 154 

vetivert 50 

Oils,  fixed 44 

volatile 46 

Ointment,  blue 81 

citrine 80, 177 

diachylon 80 

iodine 81 

iodoform 81 

mercurial 80 

mercuric  nitrate 81, 177 

oxide  of  mercury 81 

potassium  iodide 82 

rose-water  80 

salicylic  acid 80 


INDEX.  191 

PAGE 

Ointment,  tannic  acid 79 

zinc  oxide 82 

Ointments 77 

Oleate  of  atropine 174 

lead 42 

mercury 42, 174 

Oleoresin  of  capsicum 43 

cubeb 43 

lupulin 43 

male  fern 43 

Oleoresins 43 

Opium,  assay  of 132 

tincture  of 74, 134, 145 

deodorized 74 

Ox-gall 120 

Pancreatin,  solution  of 37 

Paper,  mustard 6 

Pearson's  solution ". 38 

Pepsin,  elixir  of 11 

solution  of 37 

Percolation 14 

Percolators 15 

Petrolatum 78 

Phenacetin 143 

Phenol 121, 142, 143, 146, 155,  159 

Phosphorus,  pills  of 54 

spirit  of 62 

Physostigma , 123 

assay  of 137 

extract  of 23 

Physostigmine 137 

Pills 50 

aloes  and  iron 53 

carbonate  of  iron 53, 1 74 

coating 52 

excipients 51 

iodine 53 


192  INDEX. 

PAGE 

Pills,  iron  bromide 153 

iodide 53, 174 

phosphorus 54 

Pilocarpine 137 

Pilocarpus 123 

Plaster,  court 12 

lead 12, 167 

mercurial 12 

Plasters 11 

Podophyllum 123 

resin  of 59 

Poisons,  antidotes  to 158 

Potassa,  sulphurated 109 

with  lime 109 

Potassium  acetate ^109, 143, 147 

and  sodium  tartrate Ill 

arsenite,  solution  of 34,  154,  172 

bicarbonate 109 

bromide 109 

carbonate 110, 143 

chlorate 110, 144, 145,  155 

citrate Ill,  147 

solution  of 35, 172 

cyanide Ill 

hydroxide Ill 

solution  of 35 

hypophosphite 112, 143, 156 

iodide 112, 143, 146, 155, 156 

ointment  of 82 

solution  of 141 

mercuric  iodide 144 

permanganate 113, 144 

salts  of 109 

Powder,  compound  chalk 55 

compound  effervescing 56, 174 

Dover's 56 

effervescing  caffeine  citrate 58 

glycyrrhiza,  compound 56 


INDEX.  193 

PAGE 

Powder,  ipecac  and  opium 5q 

lithium  citrate,  effervescing 58 

magnesium  citrate,  effervescing 59 

rhubarb,  compound 57 

Seidlitz 56,  174 

Powders 54 

dispensing 142 

granular  effervescing 57 

solids  not  to  be  dispensed  in  form  of 142 

Precipitation 164 

Prescriptions 138 

doses  of 139 

Pyroxylin I23 

Quinine 129, 139, 149 

Repercolation I9 

Resin  cerate g 

ot  mandrake 59 

Resins 59 

Resorcin I43 

Rochelle  salt HI 

Rose  flowers 124 

oil  of 49 

Saccharin,  solution  of 33 

Salol. 143 

Sanguinaria,  fluid  extract  of 21 

syrup  of 70 

tincture  of 75 

Santonin. 124 

Seidlitz  powder 56  1 74 

Silver  nitrate 94, 148, 166 

oxide 94 

salts  of 143, 144 

Soap 156 

liniment 28 

Sodium  borate 148, 149, 151 


194  INDEX.  . 

PAGE 

Sodium  bromide 143, 151 

carbonate 143 

dried 113 

chloride 114 

hydroxide 114 

hypophosphite 143 

iodide 114, 143 

phosphate 143, 148 

salicylate 114, 151 

sulphate 143 

sulphocarbolate 114 

Solution  of  ammonium  acetate 29, 170 

arsenous  acid 29, 169 

arsenous  and  mercuric  iodides 30 

carmin 37 

chlorinated  soda 35,  36, 173 

chlorine  compound 31, 170 

DobelPs 38 

Fowler's 34, 154, 172 

ginger 38 

gutta  percha 37 

iodine  compound 33 

iron  and  ammonium  acetate 32, 170 

chloride 31, 170 

citrate 97 

dialyzed 32 

hypophosphite 37 

iodide 37,155 

subsulphate 32, 171 

sulphate 171 

Labarraque's 35,  36, 173 

lead  subacetate 34, 1 72 

dilute 145 

lime 30,170 

magnesium  citrate,  effervescing 33, 171 

mercuric  chloride 141 

nitrate 33, 171 

Monsel's 32, 171 


INDEX.  195 

PAGE 

Solution  of  pancreatin 37 

Pearson's 38 

pepsin 37 

potassium  arsenite 34, 154, 172 

citrate 35,172 

hydroxide 35 

saccharin 38 

sodium  borate,  compound 38 

zinc  chloride 36,  1 73 

Solutions 29 

at  the  prescription  counter 140 

hypodermic 141 

of  substances  in  water 1 62 

stock 141 

Spermaceti. 119 

Spirit  of  ammonia 60 

aromatic 60, 175 

lemon 61 

myrcia 61 

nitroglycerin 61 

nitrous  ether 59, 146, 175 

peppermint 61 

phosphorus 62 

Spirits 59 

Starch,  glycerite  of 25 

Strychnine 130, 132 

Sulphur,  iodide  of 175 

precipitated 115,  175 

sublimed 115, 175 

washed 115, 175 

Suppositories 62 

chloral  hydrate 152 

glycerin 63, 176 

ichthyol 63 

iodoform 63 

tannic  acid 63 

Sweet  spirit  of  nitre 59, 146, 175 

Syrup  of  acacia 64 


196  INDEX. 

PAGE 

Syrup  of  althsea , 64 

asarum  compound 69 

calcium  iodide 69 

lactophosphate 65, 176 

with  iron 69 

citric  acid 64 

hypophosphites 67 

calcium  and  sodium 69 

compound 67 

with  iron 67 

ipecac 67, 145 

iron  citro-iodide 70 

hypophosphite 70 

iodide 65, 155, 176 

quinine  and  strychnine  phosphates 66 

lime 65, 176 

orange 64 

raspberry 68 

rhubarb 68 

sanguinaria 70 

sarsaparilla,  compound 68 

squills 68, 145 

compound 69 

tar 67 

wild  cherry 68 

yerba  santa,  aromatic 70 

Syrups 63 

Tablet  triturates 77 

Talc,  purified 115 

Tartar  emetic 93, 151 

Temperature, 161, 162 

Thermometers 161 

Thymol 143 

Tincture  of  aconite,  Fleming's 75 

arnica 71 

cinchona,  detannated 75 

fresh  herbs 71 


INDEX.  197 

PAGE 

Tincture  of  gambir,  compovmd 72 

guaiac,  compound 76 

iodine 73, 149 

Churchill's 76 

decolorized 76 

ipecac  and  opium.  , 73 

iron  chloride 72  177 

ethereal 75 

citro-chloride 76 

kino 73 

lactucarium 74 

musk 74 

myrrh I45 

nux  vomica 74 

opium 74, 134, 145 

deodorized 74 

orange 71 

rhubarb,  aqueous 74 

sanguinaria 75 

soap  bark 74 

strophanthus 75 

vanilla 75 

Tinctures 70 

Tragacanth 124, 142 

mucilage  of 41 

Trituration  of  solids 143 

Troches 77 

Turpeth  mineral 105 

Urine 157 

Veratrine 137 

Water  of  ammonia 3^  I53 

bitter  almond 4 

camphor 4 

chlorine 4 

chloroform 5 


198  INDEX. 

PAGB 

Water,  distilled 3 

hardness  of 3 

hydrogen  dioxide 5 

orange 4 

Waters,  methods  of  making 1 

preservation  of " 2 

Whiskey 61 

White  precipitate 106 

Wild  cherry,  fluid  extract  of 21 

infusion  of 27, 169 

syrup  of 68 

Wines 82 

Wool-fat,  hydrous 78 

Yerba  santa,  aromatic  syrup  of 70 

elixir  of 10 

Zinc  acetate ">  •  •  • 143 

chloride 115 

solution  of 36, 173 

oxide,  ointment  of 82 

sulphate 116, 148 


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